Innovative synthesis of 4-carbaldehydepyrrolin-2-ones by zwitterionic rhodium catalyzed chemo- and regioselective tandem cyclohydrocarbonylation/CO insertion of α-imino alkynes

The tandem cyclohydrocarbonylative/CO insertion of alpha -imino alkynes employs CO, H-2, and catalytic quantities of zwitterionic rhodium complex (eta (6)-C6H5BPh3)Rh--(+)(1,5-COD) and triphenyl phosphite affording aldehyde substituted pyrrolinones in 67-82% yields. This unique transformation is readily applied to imino alkynes containing alkyl, alkoxyl, vinyl, and aryl substituents. The ability to prepare highly functionalized pyrrolinones makes this an attractive route to these important and versatile pharmaceuticals.