Heterogenized Gold Complexes: Recoverable Catalysts for Multicomponent Reactions of Aldehydes, Terminal Alkynes, and Amines

A series of gold complexes were tested as catalysts in the synthesis of propargylamines by the three component coupling reaction of amines, aldehydes, and alkynes. These complexes are efficient catalysts for the three-component coupling reaction (yields up to 97%). In homogeneous solution, the conversions to the respective propargylamine were higher than under heterogeneous conditions. Heterogenized complexes were stable and recoverable for at least six cycles. Ligands, gold(I) or gold(III), homogeneous or heterogenized systems have pronounced effects on the catalytic activity of the corresponding gold complexes.