Stereoselective conjugate addition of metallated 2-methylpyridine to functionalized alpha, beta-unsaturated carbonyl compounds

摘要

The reaction of bis-(2-pyridylmethyl)cyanocuprate (3) with a variety of alpha, beta-unsaturated carbonyl compounds is reported. It has been found that while the reaction with enone goes through a 1,2-addition path, the outcome of the reaction with alpha, beta-unsaturated esters depends on the structure of the electrophile, giving the conjugate addition product with gamma-hetero-substituted alpha, beta-unsaturated esters. On the other hand, the reaction of 3 with oxygenated butenolides is stereoselective, affording the 1,4-addition product.