Brønsted-base-catalyzed remote cascade reactivity of 2,4-dienones – asymmetric synthesis of tetrahydrothiophenes
作者:Artur Przydacz、Rafał Kowalczyk、Łukasz Albrecht
DOI:10.1039/c7ob02397a
日期:——
developed cascade involving 1,6-addition followed by the intramolecular aldol reaction provides a straightforward access to polysubstituted tetrahydrothiophene derivatives of biological and synthetic importance. Target products, bearing threecontiguousstereocenters including one quaternary, have been obtained with excellent yields (up to 98%) and with good to high stereocontrol (>20:1 dr, up to 97:3
Site and stereoselectivity in sulfa-Michael addition to equivocally activated conjugated dienes
作者:Rafał Kowalczyk、Przemysław J. Boratyński、Aleksandra J. Wierzba、Julia Bąkowicz
DOI:10.1039/c5ra09631f
日期:——
course of sulfa-Michael addition of thiols to terminally divergently activated dienes partially incorporated in a cyclic system, as in substituted 2-(3-oxocyclohexenyl)-vinyls, can be to some extent altered by the choice of activation method. The ratio of products of competing 1,4- and 1,6-addition reactions is dependent on the potency of the electron withdrawing group. The iminiumion catalysis favors 1