History Is Brimming With Great Accomplishments And Great...

History is brimming with great accomplishments and great mistakes. Thomas Edison once replied when asked why he continued working after so many failures, â€Å"I didn t fail, I found 10,000 ways that didn t work.† This is a contrary view to the ignorant being condemned to repeating the past. People who are familiar with the past simply do not make the same mistakes. Of course they wouldn t because they know how NOT to accomplish their goals. Another way of looking at the past is tan alternate phrase, â€Å"Hindsight is 20/20.† It captures the idea that past mistakes were made and remains ambiguous whether those mistakes will or will not be made during similar future events. The Closing of the Thompson Street Pool doesn t exactly fall under the category of something that those who are ignorant of the past being doomed to repeat unless you consider the outcome and what was done to reach it. The only people who could learn anything from it are the government officia ls in charge of the budget, but let s face it, the government never learns from it s mistakes. If that were the case, our government would work on fixing our own financial problems before sending billions of dollars overseas to rebuild countries that we were at war with after EVERY war. Shouldn t the people who pay the taxes have some say in where that money goes? If I have to work to pay the government, I would like to know why my money is going to Iraq to force them to establish a government in America sShow MoreRelatedI Hear America Singing By Walt Whitman2049 Words   |  9 Pages In Walt Whitman’s poem â€Å"I Hear America Singing†, one is exposed to an America seen by the eyes of a poet, essayist and journalist during the years of one of the most important times in American history, the Civil War. From 1819 to 1892, Whitman lived through many experiences, including the atrocities and successions of the Civil War, which not only lead to the establishment of hi s multiple accredited works, but also, the creation of the prideful, positive, jubilant image of America and its citizensRead MoreLet Every Nation Know - Worksheet Answers1841 Words   |  8 Pagesstand and fight, not be an innocent bystander in the legislative process (from speech and pg. 22). He also called the current President tired and perplexed; out of touch with WWII vets. â€Å"He [Eisenhower] was detached at a time when the country was brimming with vigor†¦ When times demanded focus, he was aimless† (speech). In defense to the attacks of his Catholic faith, JFK asked this rhetorical question; â€Å"I’m able to serve in congress, and my brother was able to give his life, but we can’t be presidentRead MoreSAT Top 30 Essay Evidence18536 Words   |  75 Pages................................................. 31 Lord of the Flies, by William Golding (Murderous schoolboys stranded on an island!) ......................... 33 The Great Gatsby, by F. Scott Fitzgerald (The famous American novel) ................................................ 35 Historical Events: The American Great Depression (1929-1930s) ........................................................................................ 37 World War I (1914-1918) ..............................Read MoreFundamentals of Hrm263904 Words   |  1056 PagesStress Interview 163 The Behavioral Interview 164 Realistic Job Previews 164 Conditional Job Offers 165 Background Investigation 165 Medical/Physical Examination 167 Job Offers 168 The Comprehensive Approach 168 WORKPLACE ISSUES: Avoiding Hiring Mistakes 169 Now It’s Up to the Candidate 169 Selection for Self-Managed Teams Reliability 171 Validity 171 Content Validity 171 Construct Validity 172 Criterion-Related Validity 172 Recruiting: A Global Perspective 146 DID YOU KNOW?: Posting Online Rà ©sumà ©s

The Integrity of Humanity Explored in The Tragedy of King...

In our world, there are people like the woman who yells at her children and disciplines them with physical punishment, but also the boy who talks to the student that always sits alone at the lunch table and is socially different than others. Some people may lead a life based upon universally established morals, while others tend to let out a side of their being that is more beastly than human. Humans have the ability to make choices based on reason, while the animals of the earth have only the capacity to choose the best option for their own survival. Human reasoning, both gracious and grave is witnessed in the words of William Shakespeare’s play, The Tragedy of King Lear. Through both provocative and seemingly angelic characters,†¦show more content†¦Belief in the expression of love through action and not flattery or wealth identifies Cordelia as greater than the acquisitive and inconsiderate Lear who proves his deficiency of a moral conscience and that he has room t o deepen his understanding of human worth. A more literal form of nakedness is taken on by Edgar as he lives the seemingly degrading life of a beggar. At his worst, he declares, â€Å"Thou unsubstantial air that I embrace!/ The wretch that thou hast blown unto the worst/ Owes nothing to thy blasts.† (Shakespeare IV. I. 7-9), and realizes that for hope of a more righteous future, sometimes people must be stripped down to the core and be at their worst in order to eliminate deep-rooted habits. This interpretation of Shakespeare’s references to â€Å"nothing† suggests the importance of removing the essentially meaningless aspects of life that hold back the integral traits of humanity, and reveal the treacherous corruption that all humans are capable of. Likewise, the labels of foolishness and wisdom that are placed on characters are a false recognition of identity because of the misconception of what it means to be wise and noble or to be a foolish knave at the bas e of society. King Lear thinks of himself as wise at first, but ironically his fool proves to be wisest and claims that Lear’s actions regarding his daughters have only confirmed his folly. This makes Lear a clear example of what it means to be ignorant to the human ideaShow MoreRelatedKing Lear1057 Words   |  5 PagesShakespeare’s King Lear is a timeless play whose textual integrity lends itself to a variety of interpretations and in exploring the human condition the text remains relevant across a wide range of contexts. It is possible to present the text as exploring and affirming the human condition, where humanity is defined as the ability to love and empathise. However, in the same instance, a nihilist perspective, such as Peter Brooke’s 1971 production of King Lear, challenges this by outlining that humanity as anRead MoreWilliam Shakespeare s Much Ado About Nothing And King Lear3685 Words   |  15 PagesName: Instructors’ Name: Course: Date: Analysis of Shakespeare’s powerful female characters in the play â€Å"Much Ado about Nothing† and â€Å"King Lear Introduction Shakespeare is seen to value the role of women as his plays often portray women as heroines. These women have strong characters that endear them to readers. Readers in our current world, and especially women, are encouraged to be self-assertive in demand for equal treatment in our society. This has been the tradition for women in the Western

Grignard Reagent Free Essays

1598 Organometallics 2009, 28, 1598–1605 CoVer Essay The Grignard Reagents Dietmar Seyferth Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 ReceiVed February 4, 2009 During the past 100 years the Grignard reagents probably have been the most widely used organometallic reagents. Most of them are easily prepared in ethereal solution (usually diethyl ether or, since the early 1950s, THF) by the reaction of an organic halide with metallic magnesium (eq 1). Table 1. We will write a custom essay sample on Grignard Reagent or any similar topic only for you Order Now Composition of Diethyl Ether Solutions of Various Grignard Reagents at Equilibrium (in mol %), 2RMgX h R2Mg + MgX2a RX in RX + Mg reacn CH3I C2H5I C2H5Br C2H5Cl n-C3H7I n-C3H7Br n-C3H7Cl C6H5I C6H5Br a RMgX 87. 0 43. 0 41. 0 15. 0 24. 0 24. 0 17. 0 38. 0 30. 0 R2Mg ) MgX2 6. 5 28. 5 29. 5 42. 5 38. 0 38. 0 41. 5 31. 0 35. 0 RX + Mg f RMgX (X ) Cl, Br, I) (1) Most of them are stable in ethereal solution (although atmospheric moisture and oxygen should be excluded) and in general are quite reactive. Discovered by Victor Grignard at the University of Lyon in France in 1900,1 their ease of preparation and their broad applications in organic and organometallic synthesis made these new organomagnesium reagents an instant success. The importance of this contribution to synthetic chemistry was recognized very early, and for his discovery Grignard was awarded a Nobel Prize in Chemistry in 1912. Our cover molecule is the monomeric ethylmagnesium bromide bis(diethyl etherate) (1), whose solid-state molecular structure was determined by an X-ray diffraction study by Lloyd Guggenberger and Robert Rundle in 1964 using crystals isolated from a diethyl ether solution of a C2H5Br/Mg reaction mixture by slow cooling with a stream of cold gaseous nitrogen. 2-4 Adapted from: Schlenk, W. , Jr. Ber. Dtsch. Chem. Ges. 1931, 64, 734. Wilhelm Schlenk and his son discovered 80 years ago, more than one magnesium-containing species exists in the diethyl ether solution of a Grignard reagent. 5 A redistribution of the substituents on magnesium takes place, and the RMgX species ends up in equilibrium with the two symmetrical species, the diorganomagnesium and the magnesium dihalide: the â€Å"Schlenk Equilibrium† (eq 2). 2RMgX h R2Mg + MgX2 (2) Generally written as â€Å"RMgX† in textbooks, monographs and research papers, the Grignard reagents in ethereal solution are more complicated than this simple formula indicates. As (1) (a) Grignard, V. Compt. rend. Hebd. Seances Acad. Sci. 1900, 130, ? 1322. (b) Grignard, V. Dissertation â€Å"Theses sur les combinaisons organo` magnesie nes mixtes et leur application a des syntheses†, University of Lyon, ` ` Lyon, France, 1901. (2) (a) Guggenberger, L. J. ; Rundle, R. E. J. Am. Chem. Soc. 1964, 86, 5344. (b) Guggenberger, L. J. ; Rundle, R. E. J. Am. Chem. Soc. 1968, 90, 5375. 3) A crystalline solid, CH3MgI  · (n-C5H11)2O, was isolated and identi? ed as such by elemental analysis (Mg and I) in 1908: Zerewitinoff, Th. Ber. Dtsch. Chem. Ges. 1908, 41, 2244. The oxonium structure The species that contain Mg-halogen bonds can be precipitated from Grignard reagent solutions in diethyl ether by the addition of 1,4-dioxane. An insoluble, polymeric 1,4-dioxane adduct is formed, leaving behind a solution of R2Mg5sa useful preparation of dialkyl- and diarylmagnesium reagents. 6 Wilhelm Schlenk, Jr. analyzed the 1,4-dioxane precipitations from a number of Grignard reagent solutions. Assuming that the precipitation is essentially instantaneous, i. e. , that the calculated R2Mg, MgX2, and RMgX percentages re? ect the ac tual composition of the Grignard reagent solution at equilibrium, Schlenk reported the compositions collected in Table 1. Direct evidence (5) Schlenk, W. ; Schlenk, W. , Jr. Ber. Dtsch. Chem. Ges. 1929, 62, 920. (6) (a) Cope, A. C. J. Am. Chem. Soc. 1935, 57, 2238. (b) As Erwin Weiss found, evaporation of diethyl ether solutions of methyl- and ethylmagnesium bromide and chloride at reduced pressure followed by heating of the colorless solid residues at ca. 00  °C and 0. 001 mmHg for several hours gave a mixture of the respective pure, solvent-free, polymeric R2Mg compounds and magnesium halides. The solid MgCl2 thus obtained differed from a sample obtained from a MgCl2 melt in that its lattice showed a strong stacking disorder. This form of MgCl2 had an extremely high surface area: Weiss, E. Chem. Ber. 1965, 98, 2805. (7) Schlenk, W. , Jr. Ber. Dtsch. Chem. Ges. 1931, 64, 734 Further additions to the examples in Table 1 were soon thereafter reported by other workers: (a) Noller, C . R. ; Hilmer, F. B. J. Am. Chem. Soc. 1932, 54, 2503. (b) Johnson, G. O. Adkins, H. J. Am. Chem. Soc. 1932, 54, 1943. (c) Cope, A. C. J. Am. Chem. Soc. 1934, 56, 1578. was written for this compound. Earlier workers had isolated noncrystalline solid samples of etherates, e. g. , C2H5MgI  · (C2H5)2O and RMgI  · 2(C2H5)2O. (4) Other early Grignard reagent crystal structures: (a) Stucky, G. D. ; Rundle, R. E. J. Am. Chem. Soc. 1964, 86, 4825 (C6H5MgBr  · 2Et2O). (b) Vallino, M. J. Organomet. Chem. 1969, 20, 1 (CH3MgBr  · 3THF). . 10. 1021/om900088z CCC: $40. 75 ? 2009 American Chemical Society Publication on Web 03/16/2009 Organometallics, Vol. 28, No. 6, 2009 1599 Figure 1. Association of several Grignard compounds in tetrahydrofuran (J. Am. Chem. Soc. 1969, 91, 3847. ). that solutions of â€Å"CH3MgBr† in diethyl ether contain CH3MgBr and (CH3)2Mg was obtained by Ashby and co-workers by means of 1H NMR spectroscopic measurements at -105  °C. Solutions of â€Å"t-butylmagnesium chloride† in diethyl ether also were studied. 8 The tendency of the halide substituents in the RMgX and MgX2 species present in ethereal solution at equilibrium to form bridges between magnesium atoms, Mg-X-Mg, in a Lewis base/Lewis acid type interaction further complicates the nature of the Grignard reagent in ethereal solvents. In a very thorough study of the association factors of various Grignard reagents in diethyl ether and THF by careful ebullioscopic molecular weight measurements, Eugene Ashby and Frank Walker at the Georgia Institute of Technology found that monomeric, dimeric, and higher oligomeric species were present, depending on the solvent and the halogen and the organic substituents on the magnesium atom. 9 Included in this study along with data for the â€Å"RMgX† solutions were data for a few R2Mg compounds and for the magnesium dihalides. As Figure 1 shows, the observed association factor (the i value is the apparent molecular weight divided by the formula weight of the monoetherate) shows that the Grignard reagents and (C6H5)2Mg are close to monomeric in the relatively strong Lewis basic THF. The picture is quite different in diethyl ether solution (Figures 2 and 3), with association factors of 1 to nearly 4 for solute concentrations up to ca. 3 molal. It is not clear what these i values mean in terms of the actual species present in these solutions. On the assumption that the Schlenk equilibrium is operative in all cases, in view of the presence of a signi? cant concentration of MgX2, one cannot expect only simple solvated species of type i(R)Mg-X] n [ i (average n ) i). Toney and Stucky isolated crystals of a dimeric species, 2, from a solution of â€Å"C2H5MgBr† in di-n-butyl ether by addition of this solution to triethylamine. 10 The molecular Figure 2. Association of alkylmagnesium chlorides in diethyl ether. Demonstration of importance of halogen vs R group in determining the form of association in diethyl ether (J. Am. Chem. Soc. 1969, 91, 3848. ). Figure 3. Association of several alkyl- and arylmagnesium bromides and iodides and related magnesium compounds in diethyl ether (J. Am. Chem. Soc. 1969, 91, 3848. ). structure, as determined by X-ray analysis, contained a double Br bridge with the ethyl groups in a trans arrangement. That (8) In â€Å"CH3MgBr† solutions in diethyl ether: (a) Ashby, E. C. ; Parrish, G. ; Walker, F. Chem. Commun. 1969, 1464. (b) â€Å"(CH3)3CMgCl† solutions in diethyl ether at-26  °C: Parris, G. ; Ashby, E. C. J. Am. Chem. Soc. 1971, 93, 1206. (9) (a) Walker, F. W. ; Ashby, E. C. J. Am. Chem. Soc. 1969, 91, 3845. (b) Ashby, E. C. Bull. Soc. Chim. Fr. 1972, 2133 (review, in English). (c) Meisenheimer, J. ; Schlichenmaier. Ber. Dtsch. Chem. Ges. 1928, 61 (an earlier, similar, but more limited study in diethyl ether). more complicated structures can be present in an â€Å"RMgX† solution in diethyl ether was demonstrated by the determination of the X-ray crystal structure of a crystalline compound obtained from a THF solution of â€Å"C2H5MgCl† of composition C2H5Mg2Cl3. This compound was not a simple Cl-bridged dimer, as the empirical formula might suggest. Actually, it was a tetramer (Figure 4) in which the Mg atoms have a coordination number greater than 4. 1 There is a caveat, however: the species that crystallizes from a Grignard reagent solution does not necessarily directly re? ect what species are swimming around in the solution. The crystalline solid shown in Figure 4 could well have self-assembled during the crystallization process by combination of two molecules of the C2H5Mg2Cl3 dimer and not been present in solution at all. Even in the case of monomeric â€Å"RMgX† in THF solution, the Schlenk equilibrium will be operative and the strongly Lewis basic THF apparently prevents halide bridging between Mg atoms. Consequently, the (10) Toney, J. ; Stucky, G. D. Chem. Commun. 1967, 1168. (11) Toney, J. ; Stucky, G. D. J. Organomet. Chem. 1971, 28, 5. 1600 Organometallics, Vol. 28, No. 6, 2009 Scheme 1 Figure 4. Molecular structure of [C2H5Mg2Cl3(C4H8O)3]2, a tetrameric Grignard reagent. Modi? ed from Toney and Stucky (J. Organomet. Chem. 1971, 28, 15. (copyright 1971, with permission from Elsevier)). presence of monomeric RMgX, R2Mg, and MgX2, all solvated, would result in the measurement of an association factor of 1, as Walker and Ashby observed. There are so many factors that bear on the question of the constitution of a given Grignard reagent in ethereal solutionsthe Lewis basicity and steric properties of the ether solvent, the electronegativity and size of the halogen atom in RMgX, the nature and steric properties of the organic substituent on the magnesium atom. These will affect the magnitude of the equilibrium constant of the Schlenk equilibrium and the extent of Mg-X-Mg bridging. For most applications in synthetic chemistry it will suf? ce to take the easy way outsto regard and to write the Grignard reagent as RMgX. There is another interesting and useful property of ethereal Grignard reagent solutions. The magnesium species are weak electrolytes in such solvents of low dielectric constant, and â€Å"RMgX† solutions conduct an electric current. 12 The electrolysis of solutions of organomagnesium halides was studied in some detail by Kondyrew at the State Research Institute in Leningrad13 and by Ward Evans and his students at Northwestern University. 14 During the electrolysis, magnesium species migrate both to the cathode and to the anode. Scheme 1 shows the simplest picture based on RMgX. Metallic magnesium is formed at the cathode. 12) The earliest report appears to be a 1912 French paper: Jolibois, P. Compt. rend. Hebd. Seances Acad. Sci. 1912, 155, 213. See also: Nelson, ? J. M. ; Evans, W. V. J. Am. Chem. Soc. 1917, 39, 82. (13) (a) Kondyrew, N. W. Ber. Dtsch. Chem. Ges. 1925, 58, 459. (b) Kondyrew, N. W. ; Manojew, D. P. Ber. Dtsch. Chem. Ges. 1925, 58, 464. (c) Kondyrew, N. W. Ber. Dtsch. Chem. Ges. 1928, 61, 208. (d) Kondyrew, N. W. ; Ssusi, A. K. Ber. Dtsch. Chem. Ges. 1929, 62, 1856. (14) The Evans group published many papers in J. Am. Chem. Soc. during the 1933-1942 period. See, for example: (a) Evans, W. V. ; Lee, F. H. J. Am. Chem. Soc. 1934, 56, 654. (b) Evans, W. V. ; Field, E. J. Am. Chem. Soc. 1936, 58, 720. (c) Evans, W. V. ; Braithwaite, D. J. Am. Chem. Soc. 1939, 61, 898. (d) Evans, W. V. ; Braithwaite, D. ; Field, E. J. Am. Chem. Soc. 1940, 62, 534. (e) Evans, W. V. ; Pearson, R. J. Am. Chem. Soc. 1942, 64, 2865. The alkyl radicals formed at the anode can undergo the usual alkyl radical processes of coupling (to R-R), disproportionation (to RH + R(-H)), or, if the anode is composed of a reactive metal such as zinc, aluminum, cadmium, or lead, they can attack the anode to form an organometallic compound. A graduate student of Evans, David G. Braithwaite, joined the Nalco Chemical Co. after he graduated and developed an electrolytic process for the commercialscale syntheses of tetramethyl- and tetraethyllead antiknock agents in which the respective alkyl Grignard reagents were electrolyzed in a mixed THF/diethylene glycol dimethyl ether solvent system using a lead anode and a steel cathode. 15 The reactions of the Grignard reagents with organic, organometallic, and inorganic substrates and their applications are too numerous and varied to be covered here. Not only do they ? nd extensive use on a small to moderate scale in research laboratories but they also have been prepared and utilized on a large scale in diverse industrial processes. For the most part they react as nucleophilic reagents, as would be expected, on the basis of the polarity of the carbon-magnesium bond, C? –Mg? +. However, they also can undergo electron transfer reactions with appropriate electron-acceptor substrates. They are weak bases capable of deprotonating the stronger weak organic acids such as terminal acetylenes and cyclopentadiene. Their basicity can be enhanced (as can be the basicity of organolithium reagents) by the addition to RMgX solutions in ethers of additives such as hexamethylphosphoric triamide (HMPA) and N-methyl-2-pyrrolidinone (NMP) or alkali-metal alkoxides. All such information can be found in books devoted solely or in part to Grignard reagents. 16 Two special topics are of current interest and merit special mention. (1) The preparation of highly functionalized organomagnesium reagents by Paul Knochel and his co-workers at the University of Munich17 by means of halogen-magnesium exchange (e. . , eq 3). The availability of reagents such as 3-8 (which must be utilized at low temperature) has added a new and spectacular dimension to Grignard reagent chemistry. (2) The synthesis of ole? ns, styrenes, 1,3-dienes and biaryl derivatives by the crosscoupling of Grignard reagents with organic halides. The crosscoupling of Grignard reagents with vinylic halides was discovered by Morris Kharasch and Charl es Fuchs at the University of Chicago Organometallics, Vol. 28, No. 6, 2009 1601 Table 2. Transition Metal Halide Catalyzed Homocoupling of Phenylmagnesium Iodidea metal halide FeCl2 CoBr2 NiBr2 RuCl3 RhCl3 PdCl2 OsCl3 IrCl3 a amt, mol 0. 01 0. 01 0. 03 0. 0036 0. 0036 0. 00566 0. 00275 0. 003 amt of C6H5MgI, mol 0. 03 0. 03 0. 095 0. 0108 0. 013 0. 0163 0. 007 0. 01 yield of biphenyl, % 98 98 100 99 97. 5 98 53 28 Taken from: J. Am. Chem. Soc. 1939, 61, 957. in 1943 during the classic studies of Kharasch on the chemistry of Grignard reagents in the presence of transition-metal halides. 6b Kharasch and Fuchs found that arylmagnesium bromides in diethyl ether reacted readily with vinylic halides of type RCHdCHX and R2CdCHX (but not CH2dC(R)X) to give styrenes in 50-75% yield when the reactions were carried out in the presence of 5 mol % of CoCl2 (eq 4). 18It was reported that other metal halides (of iron, nickel, and chromium) also were effective catalysts of this cross-coupling reaction. Benzylmagnesium chloride also reacted in this manner with vinyl bromide to give PhCH2 CHdCH2 in 75% yield. Alkylmagnesium halides such as cyclohexyl- and n-butylmagnesium bromide, on the other hand, gave only â€Å"small to negligible† yields of the expected coupling product. The ArMgBrderived biaryl usually was obtained as a byproduct in these reactions. Such homocoupling of arylmagnesium halides in the presence of a transition metal halide as well as copper and silver halides was a known reaction. It had been investigated in 1939 by Gilman and Lichtenwalter, who found that aryl Grignard reagents undergo homocoupling in the presence of ca. 0 mol % of various transition-metal halides in diethyl ether solution to give the respective biaryl in high yield in most cases (eq 5, Table 2). 19 The metal halide, in addition to being the needed catalyst precursor, also served as an oxidizing agent and, in some cases (CoBr2, NiCl2, RhCl3), formation of a black solid indicated complete reduction to the metal. not occur in the absence of the organic halide but in its presence was vigorously exo thermic. The added organic halide was only partially consumed and did not show up in the biaryl product. When p-bromotoluene was added to a phenylmagnesium bromide/CoCl2 catalyst reaction mixture, only biphenyl was formed. A remarkable reaction! smost likely a free radical process, as Kharasch suggested. The organic halide was believed to function as an oxidizing agent. This interesting, simple, and potentially useful cross-coupling reaction, as exempli? ed in eq 4, was not adopted by the synthetic organic community right away. After a long dormancy it was rediscovered some 30 years later by a number of groups in the USA, Japan, and France, all of whom apparently were not aware of the 1943 Kharasch/Fuchs JACS paper. 1 Transition-metal catalysts other than CoCl2 were used, but the concept and the basic reaction were the same. In 1971 Tamura and Kochi reported a thorough study of the cross-coupling of Grignard reagents with vinylic halides catalyzed by soluble iron species in concentrations of ca. 10-4 M in THF at 0-25  °C. 26,27 Various Fe(III) compounds could be used as Fe catalyst pr ecursors; the best were Fe(III) -diketonates such as Fe(RC(O)CHC(O)R)3 (R ) Ph, CH3, t-Bu). These exothermic reactions were not free radical processes. The reactions of cis- and trans-propenyl bromide proceeded with retention of geometric con? uration (eqs 6 and 7) and were not adversely affected by the presence of 0. 4 M styrene. A ArMgBr + RCHdCHX 9 ArCHdCHR + MgBrX 8 (X ) Cl, Br) CoCl2 5 mol % (4) 2ArMgX + MXn f Ar-Ar + MgX2 + MXn-2 (5) A novel catalytic process for such ArMgX to Ar-Ar coupling was discovered by Kharasch and Fields when ethereal solutions of an aryl Grignard reagent that contained a catalytic amount (3 mol %) of CoCl2 were heated at re? ux for 1 h and then treated with an equivalent amount of an organic halide (C6H5Br, C2H5Br, i-C3H7Cl). 20 The coupling reaction to give Ar-Ar did (15) (a) Bott, L. L. Hydrocarbon Process. Petrol. Re? ner 1965, 44, 115. (b) Guccione, E. Chem. Eng. 1965, (June 21), 102. See also Part 2 of the tetraethyllead essay: (c) Seyferth, D. Organometallics 2003, 22, 5154 (pages 5172-5174). (16) (a) Krause, E. ; von Grosse, A. Die Chemie der metall-organischen Verbindungen; Gebruder Borntrager: Berlin, 1937; pp 14-61, 110-114. ? ? (b) Kharasch, M. S. ; Reinmuth, O. Grignard Reactions of Nonmetallic Substances; Prentice Hall: New York, 1954. (c) Handbook of Grignard Reagents; Silverman, G. S. , Rakita, P. E. , Eds. ; Dekker: New York, 1996. d) Grignard Reagents-New DeVelopments; Richey, H. G. , Ed. ; Wiley: Chichester, New York, 2000. (e) The Chemistry of Organomagnesium Compounds; Rappaport, Z. , Marek, L. , Eds. ; Wiley-VCH: Weinheim, Germany, 2008. (17) Knochel, P. ; Dohle, W. ; Gommermann, N. ; Kneisel, F. F. ; Kopp, F. ; Korn, T. ; Sapountzis, J. ; Vu, V. A. Angew. Chem. , Int. Ed. 2003, 42, 4302 (review). (18) Kharasch, M. S. ; Fuchs, C. F. J. Am. Chem . Soc. 1943, 65, 504. (19) Gilman, H. ; Lichtenwalter, M. J. Am. Chem. Soc. 1939, 61, 957. and earlier (back to 1914) references cited therein. 20) Kharasch, M. S. ; Fields, E. K. J. Am. Chem. Soc. 1941, 63, 2316. mechanism involving an organoiron(I) intermediate, obtained by reduction of the Fe(III) precursor by the Grignard reagent, was suggested. The results of a few experiments carried out on a 30-40 mmol scale (Table 3) showed that such iron-catalyzed reactions would be useful in the synthesis of ole? ns, but a broader study to optimize them and to broaden the scope of their application was not undertaken. The coupling of vinylic Grignard reagents with alkyl halides is catalyzed also by Ag(I) salts. 8 Thus, cis-propenylmagnesium (21) Two later â€Å"historical notes†22,23 and two book chapters24,25 that dealt with the cross-coupling reactions of Grignard reagents with vinylic halides also did not cite the Kharasch/Fuchs paper. (22) Tamao, K. J. Organomet. Chem. 2002, 653 , 27. (23) Murahashi, S. -I. J. Organomet. Chem. 2002, 653, 27. (24) Kochi, J. K. Organometallic Mechanisms and Catalysis; Academic Press: New York, 1978; Chapter 14, Sections III and IV. (25) Hou, S. ; Negishi, E. -i. In Handbook of Organopalladium Chemistry; Negishi, E. -i. , Ed. , Wiley: New York, 2002; Vol. 1,Chapter III. 2. 6, pp 335408. As a historical note, the following quotation from this reference (p 335) is of interest: â€Å"Although the reaction of Grignard reagents with organic halides was shown to be catalyzed by various late transition metal compounds (the Kharasch reaction) in the 1950s, it was not until the early 1970s that the applicability of this catalytic method was extended to the cross-coupling involving alkenyl and aryl halides catalyzed by Ag, Fe and other late transition metals. † (26) (a) Kochi, J. ; Tamura, M. J. Am. Chem. Soc. 1971, 93, 1487. (b) Tamura, M. ; Kochi, J. Synthesis, 1971, 303. (27) Full papers: (a) Neumann, S. M. ; Kochi, J. K. J. Org. Chem. 1975, 40, 599. (b) Smith, R. S. ; Kochi, J. K. J. Org. Chem. 1976, 41, 502. (c) Reviews: ref 24. (d) Kochi, J. K. J. Organomet. Chem. 2002, 653, 11 (historical note). (28) (a) Whitesides, G. M. ; Casey, C. P. J. Am. Chem. Soc. 1966, 88, 4541. (b) Tamura, M. ; Kochi, J. J. Am. Chem. Soc. 1971, 93, 1483. 1602 Organometallics, Vol. 28, No. 6, 2009 Table 3. Alkenylation of Grignard Reagents using FeCl3 as Precatalyst (in THF)a R MgBr (amt, mmol) n-C6H13MgBr (40) CH2dCH(CH2)4MgBr (36) n-C6H13MgBr (40) a 1 R2Br (amt, mmol) CH2dCHBr (204) CH2dCHBr (102) CH3CHdCHBr (355) FeCl3 (amt, mmol) 0. 05 0. 05 0. 10 reacn temp,  °C 0 25 25 product (yield, %) n-C6H13CHdCH2 (83) CH2dCH(CH2)4CHdCH2 (64) n-C6H13CHdCHCH3 (67) (53/47 cis/trans mixture) Taken from: Synthesis 1971, 6, 303. Scheme 2 bromide reacted with methyl bromide in THF in the presence of an Ag(I) catalyst to give cis-butene-2, but a similar reaction of trans-propenylmagnesium bromide gave a 7:3 mixture of cisand trans-butene-2, respectively. 28b Apparently propenyl radicals were involved. A similar Grignard reagent based cross-coupling, ole? n synthesis in which a copper(I) catalyst was used was published by French workers. 9 Normant et al. reported that their reactions (e. g. , n-Bu(Et)CdCHI + i-PrMgCl in THF at -20  °C with a Cu(I) catalyst) proceeded with retention of con? guration. 29a For a reaction of CH3CHdC(CH3)MgCl with n-C3H7I in THF at 0  °C using CuI as catalyst, Linstrumelle reported that the coupling product obtained in 97% yield was 88% cis and 12% trans, while a similar reac tion of CH2dC(CH3)MgBr with trans-n-C6H13CHdCHI gave a 4:1 trans/cis product. 29b TheuseofNi(II)catalystprecursorsforGrignardreagent-vinylic halide cross-coupling was reported in 1972 by Corriu and Masse30 and by Tamao, Sumitani, and Kumada. 1 The French group found Ni(II) acetylacetonate to be the most effective catalyst precursor, while the Japanese group favored a bis(tertiary phosphine)NiCl2 catalyst precursor and, especially, chelating diphosphine complexes such as (Ph2PCH2CH2PPh2)NiCl2. Reactions carried out in diethyl ether at re? ux generally gave excellent yields. This procedure has been carried out commercially on an industrial scale in the preparation of p-chloroand p-tert-butylstyrene. 32 Finally, the last to be discovered at that time and the most versatile procedure for the cross-coupling of Grignard reagents (29) (a) Normant, J. F. Commercon, A. ; Cahiez, G. ; Villieras, J. Compt. ? rend. Hebd. Seances Acad. Sci. , Ser. C 1974, 278, 967. (b) Derguini? Boumechal, F. ; Linstrumelle, G. Tetrahedron Lett. 1976, 3225. (30) Corriu, R. J. P. ; Masse, J. P. J. Chem. Soc. , Chem. Commun. 1972, 144. (31) (a) Tamao, K. ; Sumitani, K. ; Kumada, M. J. Am. Chem. Soc. 1972, 94, 1375. (b) See also ref 22. Later work: (c) Tamao, K. ; Kiso, Y. ; Sumitani, K. ; Kumada, M. J. Am. Chem. Soc. 1972, 94, 9268. (d) Kiso, Y. ; Tamao, K. ; Kumada, M. J. Organomet. Chem. 1973, 50, C12. (e) Kiso, Y. ; Tamao, K. ; Miyake, N. ; Yamamoto, K. ; Kumada, M. Tetrahedron Lett. 974, (No. 1), 3. (f) Tamao, K. ; Sumitani, K. ; Kiso, Y. ; Zembayashi, M. ; Fujioka, A. ; Kodama, S. ; Nakajima, I. ; Minato, A. ; Kumada, M. Bull. Chem. Soc. Jpn. 1976, 49, 1958. (g) Tamao, K. ; Kodama, S. ; Nakajima, I. ; Kumada, M. ; Minato, A. ; Suzuki, K. Tetrahedron 1982, 38, 3347. (32) Banno, T. ; Hayakawa; Umeno, M. J. Organomet. Chem. 2002, 653, 288. (33) (a) Yamamura, M. ; Moritani, I. ; Murahashi, S. -I. J. Organomet. Chem. 1975, 91, C39. Full paper: (b) Murahashi, S. -I. ; Yamamura, M. ; Yanagisaw a, K. -i. ; Mita, N. ; Kondo, K. J. Org. Chem. 1979, 44, 2408. (c) Historical note: ref 23. ith vinylic and aryl halides, that catalyzed by palladium complexes, was reported by Shun-Ichi Murahashi and coworkers in 1975. 33a The reactions were carried out in diethyl ether/benzene at room temperature using (Ph3P)4Pd as the catalyst precursor, and they proceeded stereospeci? cally in excellent yield (Scheme 2). Dang and Linstrumelle also used this procedure to prepare 1,3-dienes stereospeci? cally by the reaction of vinylic iodides with vinylic Grignard reagents. 34 Palladium-catalyzed cross-coupling of Grignard reagents with organic halides has been a very active area in organic synthesis. Reference 25 reviews (up to 2002) its application in (alkenyl) MgX-ArX, ArMgX-(alkenyl)X, and (alkenyl)MgX-(alkenyl)X coupling processes. A further chapter in this book deals with ArMgX-Ar? X coupling. 35 Another surge of research activity on cross-coupling of Grignard reagents with organic halides started around the turn of the century and still appears to be in progress at the present time (January 2009). Interest has revived in the use of iron complexes as precatalysts for the cross- and homocoupling of Grignard reagents,36 since iron complexes are cheaper than those of palladium and are nontoxic. The iron-catalyzed cross-coupling of organomagnesium bromides with vinylic bromides, although it produced ole? ns in good yield, was of interest to Jay Kochi, as noted above, primarily from the point of view of its reaction mechanism rather than of its potential for application in organic synthesis. After some 25 years several research groups carried out much experimental work which has shown iron-catalyzed cross-coupling and homocoupling of Grignard reagents to be broadly applicable and very useful additions to the methods of organic synthesis. In 1995 Gerard Cahiez, at the Universite Pierre et Marie Curie ? ? in Paris, during the course of his extensive investigations of organomanganese chemistry, found that the cross-coupling of vinylic bromides with alkyl, vinylic, and phenylmanganese chlorides could be effected in good yield in the presence of 3 mol % of iron(III) acetylacetonate in a THF/N-methyl-2pyrrolidinone (NMP) mixed solvent at room temperature. 37 In a thorough study, this reaction was extended to the crosscoupling of vinylic halides with alkylmagnesium halides using 1 mol % of Fe(acac)3 and the same solvent mixture. 8 High yields of ole? nic products were obtained. Successful crosscoupling of Grignard reagents with AcO(CH2)6CHdCHCl, CH3C(O)(CH2)3CHdCHCl, Cl(CH2)4CBrdCH2, 9, and 10 are noteworthy as examples of the selectivity and functional group tolerance of this reaction. The scope of this chemistry was extended further when some of Knochel’s functionally substituted aryl Grignard reagents17 (vide supr a) were reacted with vinylic bromides and iodides. 39 The cross-coupling reaction between aryl Grignard reagents and vinylic bromides and iodides also was found by Cahiez and co-workers to give ole? ic products in good yield with Organometallics, Vol. 28, No. 6, 2009 1603 Table 4. Iron-Catalyzed Biaryl Coupling Reactions a Table 5. Iron-Catalyzed Homocoupling of Grignard Reagents with Atmospheric Oxygen as Oxidanta a Taken from: J. Am. Chem. Soc. 2007, 129, 13788. palladium or nickel precatalysts. 42 Of these procedures, that of Cahiez et al. 41f appears to be the most useful. Alkyl halide/ alkylmagnesium halide cross-coupling is not a practical process. 43 RMgX + R? X 9 R-R? + MgX2 8 [Fe] (8) Iron-catalyzed reactions of aryl Grignard reagents with aryl halides to give biaryls generally are not synthetically useful. The desired cross-coupling products are obtained in only poor yield, the main product being the homocoupled biaryl derived from the aryl Grignard reagent (eq 9) (recall the Gilman/ Lichtenwalter and Kharasch/Fields reactions, vide supra). ArMgX + Ar? X f Ar-Ar? + (low yield) (major Ar-Ar product) (9) a Taken from: J. Am. Chem. Soc. 2007, 129, 9844. retention of geometric con? guration when carried out in THF solution in the presence of 10 mol % of MnCl2. 0 As noted above, Kharasch and Fuchs had found that attempts to cross-couple aryl Grignard reagents with alkyl halides in the presence of catalytic amounts of CoCl2 were unsuccessful. On the other hand, such reactions do occur in the presence of an iron precatalyst and various additives (eq 8, R? ) alkyl), as summarized in ref 36. A number of other groups have reported the results of their research directed tow ard development of an effective procedure for the process shown in eq 8, all using an iron precatalyst of one kind or another, various additives such as TMEDA, NMP, etc. nd generally diethyl ether (but sometimes THF) as solvent. 41 It is noteworthy that primary and secondary alkyl halides, i. e. , ones that contain hydrogen substituents on the carbon atom, can be cross-coupled with aryl Grignard reagents, a process that cannot be realized using (34) Dang, H. P. ; Linstrumelle, G. Tetrahedron Lett. 1978, 191. (35) Anastasia, L. ; Negishi, E. -i. Chapter II. 2. 5, pp 311-344, in ref 25. (To date palladium and nickel catalysts have been widely used to effect aryl-aryl cross-coupling reactions. However, arylmagnesium halides were found to undergo cross-coupling with aryl halides that contain electron-withdrawing activating substituents ortho or para with respect to the halogen substituent in the presence of 10 mol % of manganese(II) chloride (eq 10). 44 Cyclohexyl and 2-methylpropenyl G rignard reagents reacted with such substituted halobenzenes in a similar manner. Very (36) (a) Cahiez, G. ; Duplais, C. â€Å"Iron-Catalyzed Reactions of Grignard Reagents†, Chapter 13, pp 594-630 in ref 16e. (b) Furstner, A. ; Leitner, ? A. ; Mendez, M. ; Kraus, H. J. Am. Chem. Soc. 2002, 124, 13856 (a long ? paper that brings an excellent discussion of the literature, of questions concerning mechanism, and original results). (c) Sherry, B. D. ; Furstner, ? A. Acc. Chem. Res. 2008, 41, 1500. (37) Cahiez, G. ; Marquis, S. Tetrahedron Lett. 1996, 37, 1773. (38) Cahiez, G. ; Avedissian, H. Synthesis 1998, 1199. (39) Dohle, W. ; Kopp, F. ; Cahiez, G. ; Knochel, P. Synlett 2001, 1901. 1604 Organometallics, Vol. 28, No. 6, 2009 Table 6. Manganese-Catalyzed Homocoupling of Grignard Reagents with Atmospheric Oxygen as Oxidanta Scheme 4 THF to a mixture of 3 mol % of FeF3  · 3H2O and 9 mol % of an N-heterocyclic carbene (SIPr  · HCl). In one example, chlorobenzene (1. 0 equiv) and p-CH3C6H4MgBr (1. 2 equiv) were added to this catalyst system and the reaction mixture was stirred at 60  °C for 1 day. The desired product, p-CH3C6H4-C6H5, was obtained in 98% yield. The homocoupling product, biphenyl, was present only in trace amount, while CH3C6H4C6H4CH3 was formed in 3% yield. Some examples of the application of this remarkable reaction are shown in Table 4. Good results were obtained only with aryl chlorides. Aryl bromides and iodides gave low biaryl yields. A German group reported similar MnCl2-catalyzed cross-coupling between various heterocyclic chlorides and aryl as well as alkyl Grignard reagents: e. g. , eq 11. 46 a Taken from: J. Am. Chem. Soc. 2007, 129, 13788. The homocoupling reaction of aryl Grignard reagents, mentioned earlier, also has received renewed attention recently, and synthetically useful procedures have resulted. Nagano and Hayashi developed a procedure in which the reaction is carried out in re? uxing diethyl ether in the presence of 1-5 mol % of FeCl3, NMP and 1. molar equiv of 1,2-dichloroethane (which serves as the oxidant). 47 Cahiez and co-workers have improved this procedure by using THF as solvent, in which arylmagnesium halides, including the chlorides, are more easily prepared. 48 This procedure works well with Knochel’s functional arylmagnesium halides (Scheme 3). Of interest also is the clever construction of the tricyclic system 11 by intramolecul ar homocoupling (Scheme 4). (40) (a) Cahiez, G. ; Gager, O. ; Lecomte, F. Org. Lett. 2008, 10, 5255. (b) Alami, M. ; Ramiandrasoa, P. ; Cahiez, G. Synlett 1998, 325. 41) A selection: (a) Martin, R. ; Furstner, A. Angew. Chem. , Int. Ed. ? 2004, 43, 3955 (see also ref 36b and references cited therein). (b) Nagano, T. ; Hayashi, T. Org. Lett. 2004, 6, 1297. (c) Bedford, R. B. ; Bruce, D. W. ; Frost, R. M. ; Goodby, J. W. ; Hird, M. Chem. Commun. 2004, 2822. (d) Nakamura, N. ; Matsuo, K. ; Ito, S. ; Nakamura, E. J. Am. Chem. Soc. 2004, 126, 3686. (e) Bedford, R. B. ; Bruce, D. W. ; Frost, R. M. ; Hird, M. Chem. Commun. 2005, 4161. (f) Cahiez, G. ; Habiak, V. ; Duplais, C. ; Moyeux, A. Angew. Chem. , Int. Ed. 2007, 46, 4364. g) Cahiez, G. ; Duplais, C. ; Moyeux, A. Org. Lett. 2007, 9, 3253. (h) Guerinot, A. ; Reymond, S. ; Cossy, J. Angew. ? Chem. , Int. Ed. 2007, 46, 6521. (42) However, Terao and Kambe have recently developed new Pd- and Ni-based precatalyst systems which avoid the pro blem of -elimination of primary and secondary alkyl groups: Terao, J. ; Kambe, M. Acc. Chem. Res. 2008, 41, 1545. (43) (a) Tamura, M. ; Kochi, J. J. Organomet. Chem. 1971, 31, 289. (b) Rollick, K. L. ; Nugent, W. A. ; Kochi, J. K. J. Organomet. Chem. 1982, 225, 279. (44) Cahiez, G. ; Lepifre, F. Ramiandrasoa, P. Synthesis 1999, 2138. (45) Hatakeyama, T. ; Nakamura, M. J. Am. Chem. Soc. 2007, 129, 9844. (46) Rueping, M. ; Ieawsuwan, W. Synlett 2007, 247. (47) Nagano, T. ; Hiyama, T. Org. Lett. 2005, 7, 491. (48) Cahiez, G. ; Chaboche, C. ; Mahuteau-Betzer, F. Org. Lett. 2005, 7, 1943. Scheme 3 special, but generally applicable, reaction conditions developed by Japanese workers45 have ? nally provided the possibility of clean aryl-aryl cross-coupling reactions in which competitive homocoupling of the aryl Grignard reagent has been almost completely suppressed. In this procedure an active catalyst system was prepared by addition of 18 mol % of C2H5MgBr in Organometallics, Vol. 28, No. 6, 2009 1605 A further improvement resulted when it was found that atmospheric oxygen could replace the 1,2-dihaloethane as oxidant in the homocoupling of aryl, vinylic, and alkynyl Grignard reagents using either Fe or Mn catalyst precursors. 49 As Tables 5 and 6 show, this procedure gave excellent results. The most recent contribution to iron-catalyzed cross-coupling, which appeared during the preparation of the ? al draft of this paper, involves application of the old one-pot Barbier procedure in which FeCl3 served as precatalyst and stoichiometric amounts of magnesium turnings and TMEDA additive were used. A mixture of an alkyl and an aryl bromide was added to the mixture of precatalyst, TMEDA, magnesium, and solvent at 0  °C. Good yields of cross-coupled products were obtained. 50 There has been a great deal of activity in the areas of Grignard reagent/o rganic halide cross-coupling and aryl Grignard reagent homocoupling, and the coverage in this essay, whose focus is on the historical aspects, is far from exhaustive. Attention is called to the 2005 review by Frisch and Beller51 and especially (49) Cahiez, G. ; Moyeux, A. ; Buendia, J. ; Duplais, C. J. Am. Chem. Soc. 2007, 129, 13789. (50) Czaplik, W. M. ; Mayer, M. ; von Wangelin, A. J. Angew. Chem. , Int. Ed. 2009, 48, 607. (51) Frisch, A. C. ; Beller, M. Angew. Chem. , Int. Ed. 2005, 44, 674. to the recent Accounts of Chemical Research special issue on cross-coupling. 52 Since ? st reported in 1943, the cross-coupling of Grignard reagents with organic halides, thanks to further development by many later workers, has become a broadly applicable, very useful reaction in organic synthesis. There is much more about Grignard reagents that I have not covered: the various procedures used in their preparation, the mechanism of their formation (which is still controversial), the more complex organomagnesium compounds such as bis(cyclopentadienyl)magnesium, magnesium butadiene, and magnesium anthracene, and the many kinds of reactions that Grignard reage nts have been reported to undergo. But this is only a short essay, and so I have been able to cover only a few selected topics, ones which I hope will be of interest to the reader. More information can be found in the books that I have cited earlier. 16 Acknowledgment. My thanks, as always, to Professor Arnold L. Rheingold for the cover ? gure. OM900088Z (52) Acc. Chem. Res. 2008, 41, No. 11, 1439-1564, special issue. A collection of 11 reviews, many of them relevant to the subject matter of the present essay, with useful, up-to-date references. How to cite Grignard Reagent, Papers

The Atlantic System and Africa free essay sample

The Atlantic System and Africa, 1550-1800 10. Plantations in the West Indies AY. Colonization Before 1650 * 10. Spanish settlers introduced sugar-cane cultivation into the West Indies shortly after 1 500 but did not do much else toward the further development of the islands. After 1600 the F-ranch and English developed colonies based on tobacco cultivation. * 20. Tobacco consumption became popular in England in the early 16005. Tobacco production in the West Indies was stimulated by two new developments: the formation of chartered companies and the availability of cheap labor in the form of European indentured servants. 30. In the mid-sass competition from milder Virginia tobacco and the expulsion of experienced Dutch sugar producers from Brazil combined to bring the West Indian economies from tobacco to sugar production. * 40. The Portuguese had introduced sugar-cane cultivation to Brazil, and the Dutch West India Company, chartered to bring the Dutch wars against Spain to the New World, had taken control of 1 ,OOH miles of sugar-producing Brazilian coast. We will write a custom essay sample on The Atlantic System and Africa or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page Over a fifteen-year period the Dutch improved the efficiency f the Brazilian sugar industry and brought slaves from Elmira and Land (also seized from Portugal)to Brazil and the West Indies. 50. When Portugal reconnected Brazil in 1 654, the Dutch sugar planters brought the Brazilian system to the French and English Caribbean Islands. BOO. Sugar and Slaves * 10. Between 1640 and the sass colonies like Guadalupe, Martinique, and particularly Barbados made the transition from a tobacco economy to a sugar economy. In the process of doing so, their demand for labor caused a sharp and significant increase in the volume of the Atlantic slave trade. 0.The shift from European indentured servants to enslaved African labor was caused by a number of factors, including a decline in the numbers of Europeans willing to indenture themselves to the West Indies, the fact that the life expectancy of a slave after landing was longer than the term of the typical contract of indenture, and a rise in sugar prices that made planters more able to invest in slaves. 110. Plantation Life in the Eighteenth Century AY. Technology and Environment * 10. Sugar plantations both grew sugar cane and processed the cane into sugar crystals, molasses, and rum.The technology for growing and harvesting cane was simple, but the machinery required for processing (rollers, copper kettles, and so on) was more complicated and expensive. The expenses Of sugar production led planters to seek economies of scale by running large plantations. * 20. Sugar production damaged the environment by causing soil exhaustion and deforestation. Repeated cultivation of sugar cane exhausted the soil of the plantations and led the planters to open new fields, thus accelerating the deforestation that had begun under the Spanish. * 30.European colonization led to the introduction of European and African lands and animals that crowded out indigenous species. Colonization also pushed the Arrack and then the Carob people to extinction. BOO. Slaves Lives * 10. West Indian society consisted of a wealthy land-owning plutocracy, their many slaves, and a few people in between. * 20. A plantation had to extract as much labor as possible from its slaves in order to turn a profit. Slaves were organized into gangs for fieldwork, while those male slaves not doing fieldwork were engaged in specialized tasks. * 30.Slaves were rewarded for good work and punished harshly for failure to meet their reduction quotas or for any form of resistance. On Sundays, slaves cultivated their own food crops and did other chores; they had very little rest and relaxation, no education, and little time or opportunity for family life. * 40. Disease, harsh working conditions, and dangerous mill machinery all contributed to the short life expectancy of slaves in the Caribbean. The high mortality rate added to the volume of the Atlantic slave trade and meant that the majority of slaves on West Indian plantations were born in Africa. 50. Slaves frequently ran away and occasionally staged violent rebellions such as hat led by a slave named Tacky in Jamaica in 1760. European planters sought to prevent rebellions by curtailing African cultural traditions, religions, and languages. CO. Free Whites and Free Blacks * 10. In Saint Dominion there were three groups of free people: the wealthy great whites, the less-well-off little whites, and the free blacks. In the British colonies, where sugar almost completely dominated the economy, there were very few free small landholders, white or black. 20. Only a very wealthy man could afford the capital to invest in the land, machinery, and slaves needed to establish a sugar plantation. West Indian planters were very wealthy and translated their wealth into political power, controlling the colonial assemblies and even gaining a number of seats in the British Parliament. ;k 30. Slave owners who fathered children by female slaves often gave both mother and child their freedom; over time, this practice (manumission) produced a significant free black population. Another source of free black population was runaway slaves, known in the Caribbean as maroons. 1110. Creating the Atlantic Economy AY. Capitalism and Mercantilism * 10. The system of royal monopoly control of colonies and their trade as recited by Spain and Portugal in the fifteenth and sixteenth centuries proved to be inefficient and expensive. In the seventeenth and eighteenth centuries the two new institutions of capitalism and mercantilism established the framework within which government-protected private enterprise participated in the Atlantic economy. 20 . The mechanisms of early capitalism included banks, joint-stock companies, stock exchanges, and insurance. * 30. Mercantilism was a number of state policies that promoted private investment in overseas trade and accumulation of capital in the form of precious metals. The instruments of mercantilism included chartered companies, such as the Dutch West India Company and the French Royal African Company, and the use of military force to pursue commercial dominance. * 40.The French and English eliminated Dutch competition from the Americas by defeating the Dutch in a series of wars between 1652 and 1678. The French and the English then revoked the monopoly privileges of their chartered companies, but continued to use high tariffs to prevent foreigners from gaining access to trade with their colonies. The Atlantic became the major trading area for the British, the French, and the Portuguese n the eighteenth century. 80. The Atlantic Circuit * 10.The Atlantic Circuit was a clockwise network of trade routes going from Europe to Africa, from Africa to the plantation colonies Of the Americas (the Middle Passage), and then from the colonies to Europe. If all went well, a ship would make a profit on each leg of the circuit. * 20. The Atlantic Circuit was supplemented by a number of other trade routes: Europe to the Indian Ocean, Europe to the West Indies, New England to the West Indies, and the Triangular Trade between New England, Africa, and the West Indies. 30. As the Atlantic system developed, increased demand for sugar in seventeenth and eighteenth century Europe was associated with an increase in the flow of slaves from Africa to the New World. * 40. The slave trade was a highly specialized business in which chartered companies(in the seventeenth century) and then private traders (in the eighteenth century) purchased slaves in Africa, packed them into specially designed or modified ships, and delivered them for sale to the plantation colonies. * 50.Disease, maltreatment, suicide, and psychological depression all contributed to the average death rate of one out of every six slaves shipped on the Middle Passage. Disease was the single most important cause of death, killing the European crewmen of the slave ships at roughly the same rate as it killed the slaves themselves. VIVO. Africa, the Atlantic, and Islam AY. The Gold Coast and the Slave Coast * 10. European trade with Africa grew tremendously after 1 650 as merchants sought to purchase slaves and other goods.The growth in the slave trade was accompanied by continued trade in other goods, but it did not lead to any significant European colonization Of Africa. 20. African merchants were discriminating about the types and the amounts of merchandise that they demanded in return for slaves and other goods, and they raised the price of slaves in response to increased demand. African governments on the Gold and Slave Coasts were strong enough to make Europeans observe African trading customs, while the Europeans, competing with each other for African trade, were unable to present a strong united bargaining position. 30. Exchange of slaves for firearms contributed to state formation in the Gold and Slave Coasts. The kingdom of Doomed used rearms acquired in the slave trade in order to expand its territory, while the kingdoms of Oho and Sensate had interests both in the Atlantic trade and in overland trade with their northern neighbors. * 40. The African kings and merchants of the Gold and Slave Coasts obtained slaves from among the prisoners of war captured in conflicts between African kingdoms. BOO. The Bight of Bavaria and Angola * 10.There were no sizeable states-?and no large-scale wars-?in the interior of the Bight of Bavaria; kidnapping was the main source of people to sell into slavery. African traders who specialized in procuring people for he slave trade did business at inland markets or fairs and brought the slaves to the coast for sale. * 20. In the Portuguese-held territory of Angola, Afro- Portuguese caravan merchants brought trade goods to the interior and exchanged them for slaves, whom they transported to the coast for sale to Portuguese middlemen, who then sold the slaves to slave dealers for shipment to Brazil.Many of these slaves were prisoners of war, a byproduct generated by the wars of territorial expansion fought by the federation of Landau kingdoms. * 30. Enslavement has also been linked to environ mental rises in the interior of Angola. Droughts forced refugees to flee to kingdoms in better-watered areas, where the kings traded the grown male refugees to slave dealers in exchange for Indian textiles and European goods that they then used to cement old alliances, attract new followers, and build a stronger, larger state. * 40.Although the organization Of the Atlantic trade varied from place to place, it was always based on a partnership between European traders and a few African political and merchant elites who benefited from the trade while many more Africans suffered from it. CO. Africans European ND Islamic Contacts * 10. In the centuries between 1550 and 1800 Europeans built a growing trade with Africa but did not acquire very much African territory. The only significant European colonies were those on islands; the Portuguese in Angola, and the Dutch Cape Colony, which was tied to the Indian Ocean trade rather than to the Atlantic trade. 20. Muslim territorial dominance was much more significant, with the Ottoman Empire controlling all of North Africa except Morocco and with Muslims taking large amounts of territory from Ethiopia. In the 1 sass Morocco attacked the sub-Sahara Muslim mining Of Shanghai, occupying the area for the next two centuries and causing the bulk of the trans-Sahara trade in gold, textiles, leather goods, and kola nuts to shift from the western Sudan to the central Sudan. * 30.The trans-Sahara slave trade was smaller in volume than the Atlantic slave trade and supplied slaves for the personal slave army of the Moroccan rulers as well as slaves for sugar plantation labor, servants, and artisans. The majority of slaves transported across the Sahara were women destined for service as concubines or servants and children, including eunuchs, meant for revive as harem guards. * 40. Muslims had no moral objection to owning or trading in slaves, but religious law forbade the enslavement of fellow Muslims.Even so, some Muslim states south of the Sahara did enslave African Muslims. * 50. Muslim cultural influences south of the Sahara were much stronger than European cultural influences. Islam and the Arabic language spread more rapidly than Christianity and English, which were largely confined to the coastal trading centers. * 60. The European and Islamic slave trade could not have had a significant effect on the overall population of he African continent, but they did have an acute effect on certain areas from which large numbers of people were taken into slavery.The higher proportion of women taken across the Sahara in the Muslim slave trade magnified its long-term demographic effects. 70. The volume Of trade goods imported into sub-Sahara Africa was not large enough to have had any significant effect on the livelihood of traditional African artisans. Both African and European merchants benefited from this trade, but Europeans directed the Atlantic system and derived greater benefit from it than the African merchants did.