Enantioselective Synthesis of Amaryllidaceae Alkaloids (+)-Vittatine, (+)-epi-Vittatine, and (+)-Buphanisine

Cat. on a hot tin roof: Enantioselective catalytic Michael addition of ??-cyanoketones to acrylates under bifunctional organocatalysis was used to construct the unique arylic all-carbon quaternary stereocenter, which is synthetically crucial in the chemical synthesis of optically pure cis-aryl hydroindole alkaloids. The protocol offers an asymmetric route to (+)-vittatine, (+)-epi-vittatine, and (+)-buphanisine. Copyright ? 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.Chemistry, MultidisciplinarySCI(E)EI1ARTICLE91966-1971