Structural Requirements for Palladium Catalyst Transfer on a Carbon-Carbon Double Bond

Intramolecular transfer of (Bu3PPd)-Bu-t(0) on a carbon carbon double bond (C=C) was investigated by using Suzuki-Miyaura coupling reaction of dibromostilbenes with aryl boronic acid or boronic acid esters in the presence of various additives containing C=C as a model. Substituent groups at the ortho position of C=C of stilbenes are critical for selective intramolecular catalyst transfer and may serve to suppress formation of the bimolecular C=C-Pd-C=C complex that leads to intermolecular transfer of (Bu3PPd)-Bu-t(0).