Copper-mediated 1,6-, 1,8-, 1,10-and 1,12-addition and 1,5-substitution reactions in organic synthesis

Of all the organometallic reagents currently used to form carbon-carbon bonds, organocopper compounds rank amongst the most important. Classical applications of these reagents involve carbocupration, 1,4-Michael addition and 1,3-(S(N)2')-substitution reactions. Recently, the scope of organocopper chemistry has been broadened significantly by the development of 1,6-, 1,8-, 1,10-, and 1,12-addition reactions, as well as of 1,5-substitution reactions of multiply unsaturated substrates which often contain at least one triple bond. These new transformations not only proceed with high regio- and stereoselectivity and can therefore be utilized in target-oriented synthesis, e.g. of functionalized allenes, but they also provide new information about the mechanism of copper-mediated carbon-carbon bond forming reactions. In this account some of the more recent important developments in this area are discussed. (C) 1999 Elsevier Science S.A. All rights reserved.