Ruthenium-Catalyzed Tandem Ring-Opening/Ring-Closing/Cross-Metathesis of 1,6-Cyclopropene-ynes and Olefins for the Construction of the 3-Pyrroline Skeleton

Catalyzed by the first-generation Grubbs’ ruthenium complex, tandem intramolecular/intermolecular metathesis of 1,6-enynes bearing a cyclopropene ring took place smoothly to produce 3-pyrroline derivatives in satisfactory yields via ring-opening/ring-closing/cross-metathesis processes.