Gold Catalysis and Chiral Sulfoxides: Enantioselective Synthesis of Dihydroisoindol-4-ols

Furfurals and enantomerically pure sulfinamides have been condensed to N-sulfinylimines. Addition of organolithium or -magnesium compounds to these imines allowed a 1,2-induction. After propargylation, the sulfinamides gave low conversion with gold catalysts. Oxidation to chiral sulfonamides, propargylation and gold-catalysed cycloisomeriza- tion to the phenol delivered non-racemic dihydroisoindol-4ols in good yields. In situ NMR studies prove the intermediacy of the arene oxide even with the AuCl3 catalyst. ((C)Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)