The ruthenium catalyzed formation of chiral dihydropyrrolones from α,β-unsaturated imines: extending the reaction to terminal alkenes and investigating the formation of pyrroles as side-products

The reaction of α,β-unsaturated imines derived from cinnamaldehyde with CO and various alkenes produces chiral 1,3-dihydropyrrolone derivatives. As a byproduct the formation of 2,3-disubstituted pyrroles is observed in every reaction. If the imines are reacted with ethylene only, products with an ethyl group at C-3 of the imine chain are formed. The implications of these findings on the reaction mechanism are discussed.