Ring Expansion to 8-Membered Silacycles via Formal Cross-Dimerization of 5-Membered Palladacycles with Silacyclobutanes

Investigations of the sila-8-membered ring fused biaryls are of important significance for the discovery of new drug lead compounds. However, such compounds are still unknown due to the synthetic challenge. Herein we describe the chemo- and regio-selective cross-dimerization of 5-membered palladacycles with silacyclobutanes enabled by Pd-catalytic conditions, which constitutes an expedient ring expansion route to the sila-8-membered ring fused biaryl skeletons.