Polarity inversion of donor-acceptor cyclopropanes: disubstituted δ-lactones via enantioselective iridium catalysis.

ABSTRACT: The coupling of carbonyl electrophiles at the donor position of donor-acceptor cyclopropanes is described, representing an inversion of polarity with respect to conventional reactivity modes displayed by these reagents. Specifically, upon exposure of donor-acceptor cyclopropanes to alcohols in the presence of a cyclometalated iridium catalyst modified by (S)-BINAP, catalytic C-C coupling occurs, providing enantiomerically enriched products of carbonyl allylation. Identical products are obtained upon isopropanol-mediated transfer hydrogenation of donor-acceptor cyclopropanes in the presence of aldehydes. The reaction products are directly transformed to cis-4,5-disubstituted δ-lactones.

SUBMITTER: Moran J 

PROVIDER: S-EPMC3218199 | biostudies-literature | 2011 Nov

REPOSITORIES: biostudies-literature