Phosphine-Catalyzed Cascade Annulation of MBH Carbonates and Diazenes: Synthesis of Hexahydrocyclopenta[c]pyrazole Derivatives
Hongxiang Li, Wangyu Shi, Chang Wang, Hao Liu, Wei Wang, Yongjun Wu, Hongchao Guo
Abstract
A phosphine-catalyzed cascade annulation of Morita-Baylis-Hillman (MBH) carbonates and diazenes was achieved, giving tetrahydropyrazole-fused heterocycles bearing two five-membered rings in moderate to excellent yields. The reaction underwent an unprecedented reaction mode of MBH carbonates, in which two molecules of MBH carbonates were fully merged into the ring system.
Topics & Concepts
AnnulationChemistryPhosphineCatalysisPyrazoleMedicinal chemistryCascadeRing (chemistry)Combinatorial chemistryOrganic chemistryChromatographySulfur-Based Synthesis TechniquesAsymmetric Synthesis and CatalysisCyclopropane Reaction Mechanisms