The reaction of copper(II) complexes of glycine imines with activated olefins

Abstract

The reaction between N-pyruvoylideneglycinatocopper(II) and several activated olefins has been investigated. The products of the reaction are substituted proline derivatives which probably form by cyclization of the Michael adducts intermediates. The organic products have been isolated and characterized through their i.r., ¹H n.m.r., ¹³C n.m.r. and mass spectra. The stereoisomeric composition of the products suggests that the cyclization occurs with a rather high degree of stereoselectivity. The possibility that the proline derivatives are formed via direct 1,3-anionic cycloaddition is presently discarded since this reaction is expected to occur with stereospecificity.