Ruthenium complexes of the general formula [RuCl2(PHOX)2] as precatalysts in propargylic substitution reactions

Abstract

After activation by chloride abstraction utilizing NaBArF as an activator (BArF=tetrakis(3,5-bis(trifluoromethyl)phenyl)borate), a complex of the general formula [RuCl2(PHOX)2] was utilized as a catalyst in propargylic substitution reactions, where PHOX is a phosphinooxazoline ligand. Oxygen and nitrogen-centered nucleophiles could be employed in the substitution of a propargylic acetate to obtain the corresponding propargylic substitution products in 87% to 9% isolated yields (45°C, 16h reaction time, toluene solvent, 1–2mol% catalyst loading, 1–2mol% activator).