Stereoselective synthesis of triarylethylenes via copper-palladium catalyzed decarboxylative cross-coupling: synthesis of (Z)-tamoxifen.

The first Cu/Pd-catalyzed decarboxylative cross-coupling of 3,3-diarylacrylic acids with aryl bromides is described. Triarylethylenes were obtained in high yields with excellent stereoselectivities. This methodology was successfully applied to the stereoselective synthesis of (Z)-tamoxifen.