Development of C-C Bond Formation and Asymmetric Reactions Catalyzed by N-Heterocyclic Carbenes

Abstract

  N-Heterocyclic carbenes have been studied for their ability to catalyze C-C bond formations and asymmetric reactions. The fluoro groups of fluorobenzenes are nucleophilically substituted with aroyl groups derived from aromatic aldehydes due to the catalytic action of imidazolidenyl carbenes to afford ketones. N-Heterocyclic carbenes mediate the addition of trimethylsilyl cyanide to aldehydes to yield cyanohydrin trimethylsilyl ethers. The use of chiral imidazolidenyl carbenes derived from (R,R)-1,3-bis[(1-naphthyl)ethyl]imidazolium chloride led to enantioselective cyanosilylation. C₂-symmetric imidazolidenyl carbenes catalyze the asymmetric acylation of racemic secondary alcohols.