Chiral Organotin Hydride Catalyzed Enantioselective Radical Cyclization of Aldehydes

Cat on a hot tin radical: Chiral organotin-hydride-catalyzed enantioselective radical cyclization of aldehydes has been achieved. The reaction is efficiently promoted by a catalytic amount (10 mol %) of a chiral tin hydride to produce chromanol derivatives with moderate enantioselectivity. The utility of chiral organotin hydride was also demonstrated in catalytic enantioselective radical reduction.