α-Diimine-Niobium Complex-Catalyzed Deoxychlorination of Benzyl Ethers with Silicon Tetrachloride

Abstract

α-Diimine niobium complexes serve as catalysts for deoxygenation of benzyl ethers by silicon tetrachloride (SiCl 4 ) to cleanly give two equivalents of the corresponding benzyl chlorides, where SiCl 4 has the dual function of oxygen scavenger and chloride source with the formation of a silyl ether or silica as the only byproduct. The reaction mechanism has two successive transetherification steps that are mediated by the niobium catalyst, first forming one equivalent of benzyl chloride along with the corresponding silyl ether intermediate that undergoes the same reaction pathway to give the second equivalent of benzyl chloride and silyl ether.

Syntheses of Dianionic α-Iminopyridine Rare-Earth Metal Complexes and Their Catalytic Acitivities toward Dehydrogenative Coupling of Amines with Hydrosilanes

“…The coordination modes of α-diimine ligands are flexible, and their possible modes are depicted in Chart , showing that the corresponding ligands coordinate to one or two metals in neutral, monoanionic, and dianionic modes ( A – H , Chart ). Lanthanide and actinide complexes containing the α-diimine ligands have been reported widely in recent years . The redox reactions of the divalent lanthanide complexes with α-diimine ligands affording various trivalent rare-earth metal complexes containing radical-anionic α-diimine ligands have received increasing attention .…”