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

ORGN 682

Xavier Companyó,, Andrea-Nekane Alba,, Francisco Cárdenas, Albert Moyano,, and Ramon Rios, 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.