Palladium-catalyzed(4+4) Annulation To Eight-membered Silacycles Via C–H And C–Si Bonds Activation

Construction of eight-membered silacycles via Pd-catalyzed(4+4)annulation of silacyclobutanes and 2-iodobiphenyl derivatives is described in this thesis.Organosilicon compounds are widely applicable in industry while the efficient and selective construction of C–Si bond is an important method to synthesize new organosilicon molecules,which is of great significance in new drug discovery and material synthesis.This strategy involves direct C–H and C–Si bonds activation followed by a ring annulation to construct the new C–C and C–Si bonds accessing a series of eight-membered silacycles with the Pd(OAc)as the catalyst and KOAc as the base,which features low catalyst loading(2.5 mol%),ligand-free conditions.Mechanistic studies revealed the involvement of five-membered palladacycle species in the reaction.This methodology offers new insights of silacyclobutanes transformation and provides a straightforward approach to eight-membered silacycles for potential applications in pharmaceuticals.