Rhodium-Catalyzed Addition of Alkynes to Activated Ketones and Aldehydes

Abstract

[reaction: see text] The rhodium-catalyzed addition of alkynes to 1,2-diketones, 1,2-ketoesters, and aldehydes provides a method for the synthesis of tertiary alkynyl alcohols under mild conditions. The reaction tolerates many functional groups (such as carboxylic acids) that are incompatible with other methods. The alkyne addition reaction proceeds best using bulky phosphine ligands such as 2-(di-tert-butylphosphino)biphenyl. This method fills a void in the more common zinc-catalyzed processes, which give poor yields with enolizable 1,2-dicarbonyl substrates.