Enantioselective radical-mediated reactions of carbonyl compounds with organotin reagents

Selected recent examples of enantioselective radical-mediated reactions of carbonyl compounds by use of organotin reagents are reviewed. Enantioselect ive reduction, allylations and cyclizations of a-halocarbonyl compounds pro moted by chiral Lewis acids have met with success. Employment of chiral org anotin hydrides has been also successful in yielding optically active compo unds. Furthermore, hydrogen atoms and allyl groups can be transferred enant ioselectively to radicals undergoing additions to alpha, beta -unsaturated carbonyl compounds in the presence of chiral Lewis acids. beta -Enantiosele ctive radical additions catalyzed by chiral Lewis acids can be achieved. In addition, there are some cases where external achiral ligands show remarka ble effects on asymmetric induction.