Simple and General Procedure for the Synthesis of α,β-Alkynyl Ketones from Nitriles Using Alkynyldimethylaluminum Reagents

A simple and efficient approach for the synthesis of ,-alkynyl ketones from nitriles and alkynyldimethylaluminum reagents, derived from trimethylaluminum and alkynes, is described. This methodology provides access to a wide range of ,-alkynyl ketones with aliphatic, aromatic, and heteroaromatic substituents in moderate to high yield (53-90%). In the cases of aryl-substituted nitriles, the product can also be obtained as ,-alkynyl N-H ketimines in high yield (88-93%).