SYNTHESIS OF CYCLOPROPYLPYRROLIDINES VIA REACTION OF N-ALLYL-N-PROPARGYLAMIDES WITH A MOLYBDENUM CARBENE COMPLEX - EFFECT OF SUBSTITUENTS AND REACTION CONDITIONS

Previous studies have demonstrated that group 6 carbene complexes reac t with alpha,omega-enynes to form vinylcyclopropane derivatives in goo d to excellent yield, and that the length and composition of the tethe r between the alkyne and the alkene often has a dramatic impact on the viability of this reaction pathway. The reactivity of allylpropargyl amine derivatives with pentacarbonyl(1-methoxypentylidene)molybdenum(0 ) (14a) was investigated in order to provide further insight into the steric and electronic factors controlling this reaction. Treatment of allylpropargyl amines with 14a failed to produce the desired cyclizati on products while treatment of allylpropargyl amides with 14a led to t he expected cyclopropylpyrrolidine systems in good to excellent yields . Higher yields are obtained when the reaction is conducted in a seale d vial in the presence of atmospheric oxygen.