Asymmetric organocatalytic cyclopropanation: Highly stereocontrolled synthesis of chiral cyclopropanes with quaternary stereocenters

ORGN 682

Xavier Companyó, x.companyo@hotmail.com, Andrea-Nekane Alba, n3k4n3@yahoo.es, Francisco Cárdenas, Albert Moyano, amoyano@ub.edu, and Ramon Rios, riosramon@yahoo.com. Departament de Química Orgànica, Universitat de Barcelona, Martí i Franquès, 1-11, Barcelona, 08028, Spain
A convenient and novel domino reaction for the synthesis of highly functionalized cyclopropanes is reported. The addition of 2-bromoketoesters to a variety of a,b-unsaturated aldehydes catalyzed by secondary amines leads to chiral cyclopropanes with three stereogenic carbons, including one quaternary stereocenter, in a highly stereocontrolled fashion.