Organocopper Reagents

Copper(I) Catalyzed Reactions of Organolithium and Grignard Reagents,
  Erdik, E. Tetrahedron 1984, 40, 641.
Copper Assisted Nucleophilic Substitution of Aryl Halogen,
   Lindley, J. Tetrahedron 1984, 40, 1433.
Organocopper Reagents: Substitution, Conjugate Addition, Carbo/Metallocupration, and Other Reactions,
  Lipshutz, B. H.; Sengupta, S. Org. Reactions 1992, 41, 135.
Selective Synthesis by Use of Lewis Acids in the Presence of Organocopper and Related Reagents,
  Yamamoto, Y. Angew. Chem. I.E. 1986, 25, 947.
Applications of Higher-Order Mixed Organocuprates to Organic Synthesis,
  B. H. Lipshutz Synthesis 1987, 325.
SN2' Additions of Organocopper Reagents to Vinyloxiranes,
  Marshall, J. A. Chem. Rev. 1989, 89, 1503.
New Tools in Synthetic Organocopper Chemistry,
  Nakamura, E. Synlett 1991, 539.
New Aspects of Organocopper Reagents: 1,3- and 1,2-Chiral Induction and Reaction Mechanism,
  Ibuka, T.; Yamamoto, Y. Synlett 1992, 769.
Transmetalation reactions in organocopper chemistry,
  Wipf, P. Synthesis 1993, 537.
Recent Progress in Higher Order Cyanocuprate Chemistry,
  Lipshutz, B.H. Adv. Metal-Organic Chem. Vol. 4, 1995, JAI: Greenwich, Connecticut.
Regioselective and Stereoselective Syntheses with Organocopper Reagents,
  Krause, N.; Gerold, A. Angew. Chem. Int. Ed. Engl. 1997, 36, 187-204.

  

The alkylcopper species generally have lower stability and reactivity than the cuprates, and are sometimes insoluble, so they are not used extensively. Their solubility and reactivity can be improved by complexation with Lewis acids (BF3 or MgBr2) or Lewis bases (phosphines). The dialkyl cuprates are the most generally useful, and most synthetic applications make use of these. Because only one of the ligands are transferred (after the first transfer the product is a usually unreactive alkylcopper), a variety of mixed cuprates have been developed in which one of the ligands does not transfer rapidly (typically cyanide or an acetylide is used, but many other groups such as other stabilized organolithium reagents (thienyllithium, lithiosulfones), dialkyl amides, phosphides or thiolates can be used.

Organocopper reagents are most frequently made by transmetalation of lithium reagents, but organomagnesium, organozinc and organoboron compounds can also be transmetalated The reactions with lithium reagents generally require a stoichiometric amount of copper salt, so no free lithium reagent remains, since the lithium reagent itself is very reactive toward most substrates. In contrast, the reactions with Grignard and zinc reagents can be catalytic in copper, since the these organometallic reagents are less reactive than the organocopper species with typical substrates.

  

There are three principal reactions where the organocopper species are more effective than their precursor organolithium or organomagnesium reagents: conjugate addition to a,b-unsaturated carbonyl compounds, coupling with alkyl halides, epoxides or tosylates, and carbometalation of acetylenes.

Organocopper reagents do not react rapidly with ketones, ester or amides, but will react with aldehydes, a,b-unsaturated ketones and esters, acyl halides, alkyl, aryl and vinyl bromides and iodides, epoxides, as well as allyl and propargyl acetates.


Web page created by WINPLT, (c) Hans J. Reich, 2004, All Rights Reserved