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Organocopper compounds in organometallic chemistry contain carbon to copper chemical bonds. Organocopper chemistry is the science of organocopper compounds describing their physical properties, synthesis and reactions. They are reagents in organic chemistry. The first organocopper compound, the explosive copper(I) acetylide Cu2C2 (Cu-C≡C-Cu), was synthesized by Rudolf Christian Böttger in 1859 by passing acetylene gas through copper(I) chloride solution: :C2H2 + 2 CuCl → Cu2C2 + 2 HCl Henry Gilman prepared methylcopper in 1936. In 1941, Kharash discovered that reaction of a Grignard reagent with cyclohexenone in presence of Cu(I) resulted in 1,4-addition instead of 1,2-addition.〔 In 1952 Gilman investigated for the first time dialkylcuprates. In the 1960s, complexes of alkenes and CO with copper(I) were established. ==Chemical Properties== Organocopper compounds are very reactive towards oxygen and water, forming copper(I) oxide and tend to be thermally unstable. Because most cuprates are salts, many are generally insoluble in nonpolar solvents. Despite these difficulties, organocopper reagents are frequently generated and consumed in situ with no attempt to isolate them. They are used very frequently in organic chemistry as alkylating reagents because they exhibit more functional group tolerance than corresponding Grignard and organolithium reagents. The electronegativity of copper is much higher than its next-door neighbor in the group 12 elements, zinc, suggesting less nucleophilicity for its carbon ligands. The oxidation state of copper can be +1 or +2 and intermediates can have oxidation state +3. Monovalent alkylcopper compounds (RCu) are polymeric but form cuprates (R2CuLi) upon treatment with organolithium compounds (RLi). These cuprates are sometimes referred to as Gilman reagents. Organocopper compounds can be stabilized by complexation to a variety of ligands such as alkylphosphines (R3P), thioethers (R2S), and cyanide (CN−). The cuprate complexes form complicated aggregates both in crystalline form and in solution. Lithium dimethylcuprate is a dimer in diethyl ether forming an 8-membered ring with two lithium atoms coordinating between two methyl groups. Similarly, lithium diphenylcuprate forms a dimeric etherate, ()2, in the solid state. : The first ever crystal structure was determined in 1972 by Lappert for CuCH2SiMe3. This compound is relatively stable because the bulky trimethylsilyl groups provide steric protection. It is a tetramer, forming an 8-membered ring with alternating Cu-C bonds. In addition the four copper atoms form a planar Cu4 ring based on three-center two-electron bonds. The copper to copper bond length is 242 pm compared to 256 pm in bulk copper. In ''pentamesitylpentacopper'' a 5-membered copper ring is formed, similar to (2,4,6-Trimethylphenyl)gold, and ''pentafluorophenylcopper'' is a tetramer.〔 Vol. 59, p.122 (1979)〕 With carbon monoxide copper forms a non-classical metal carbonyl. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Organocopper compound」の詳細全文を読む スポンサード リンク
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