A Palladium-Catalyzed Regio- and Stereoselective Four-Component Coupling Reaction
journal contributionposted on 04.02.2005, 00:00 by Daniel J. Knapton, Tara Y. Meyer
Pd(PPh3)4 catalytically assembles sulfenamide, alkyne, carbon monoxide, and diphenyl diselenide regio- and stereoselectively in a one-pot four-component coupling reaction to yield (Z)-β-selenyl acrylamides. The reaction proceeds in good to excellent yields (60−95%) and is tolerant of a range of functional groups on both the nitrogen of the sulfenamide and the alkyne. Moderate selectivities ranging from 4:1 to 7:1 β-selenyl to β-sulfenyl acrylamide have been observed despite the initial concentration of 2:1 selenium to sulfur in the reaction. The chalcogeno selectivity was found to depend directly on CO pressure; increased pressure decreased selectivity for selenium over sulfur.