Rhodium-Catalyzed Oxygenative Addition of Alcohols and Amines to Terminal Alkynes for the Synthesis of Esters and Amides

Abstract

A rhodium-catalyzed reaction has been developed, in which terminal alkynes undergo an oxygenative addition with alcohols and amines to produce the corresponding esters and amides as the products. In this process, the rhodium vinylidene generated from a terminal alkyne is converted to a rhodium ketene complex by oxygen transfer from sulfoxides or N-oxides. Subsequently, the addition of nucleophiles such as alcohols and amines to the ketene complex gives esters and amides. Mechanistic studies suggest that the catalytic reaction involves the formation of a rhodium ketene complex via the oxidation of the metal-bound unsaturated carbene.