Gold(I)-catalyzed enantioselective synthesis of benzopyrans via rearrangement of allylic oxonium intermediates.

ABSTRACT: The first transition metal catalyzed asymmetric carboalkoxylation reaction of propargyl esters is described. The (R)-MeO-DTBM-BIPHEP(AuCl)(2)-catalyzed reactions allow for the construction of benzopyrans containing quaternary stereocenters with excellent enantioselectivity. Experimental evidence supports a mechanism proceeding via the generation of a stabilized carbocation from an allylic oxonium intermediate and subsequent trapping by a chiral allylgold(I) spieces.

SUBMITTER: Uemura M 

PROVIDER: S-EPMC2664525 | biostudies-literature | 2009 Mar

REPOSITORIES: biostudies-literature