Rh-Catalyzed Animation of Ethereal C~alpha-H Bonds:A Versatile Strategy for the Synthesis of Complex Amines

摘要

The recent advancement of highly selective catalytic methods for the amination of OH bonds has inspired novel approaches to complex natural products.Our efforts to expand this chemistry further have led to the identification of a distinct class of l,2,3-oxathiazinane-2,2-dioxide heterocycles 2,made accessible through sulfamate ester 1 insertion into ethereal C~alpha-H centers(Scheme I).Herein,we demonstrate a simple and effective method,which capitalizes on catalyst-controlled regioselective C-H oxidation,for assembling these unique N,O-acetals 2.Such compounds display exceptional versatility as iminium ion equivalents,coupling smoothly and with high diasteroinduction to allyl silanes,enol ethers,silyl ketene acetals,and,as reported previously,alkynyl zinc reagents.