Asymmetric Construction of Bispiro‐Cyclopropane‐Pyrazolones via a [2+1] Cyclization Reaction by Dipeptide‐Based Phosphonium Salt Catalysis
Dongming Lu, Xin Liu, Jia‐Hong Wu, Song Zhang, Jian‐Ping Tan, Xiaojun Yu, Tianli Wang
Abstract
Abstract We reported herein an efficient alternative for asymmetric synthesis of structurally complicated chiral bispiro‐cyclopropane‐pyrazolones via dipeptide‐based phosphonium salt catalyzed [2+1] cyclization of 2,3‐dioxopyrrolidines and halogenated pyrazolones. With this catalytic asymmetric protocol, a broad range of bispiro heterocyclic compounds bearing a pyrazolone unit were prepared in high yields with excellent diastereo‐ and enatioselectivities. Of note, this transformation proceeds in a really short time under mild reaction conditions. magnified image
Topics & Concepts
PyrazolonesChemistryCyclopropanePyrazolonePhosphonium saltCatalysisDipeptideSalt (chemistry)PhosphoniumCombinatorial chemistryOrganic chemistryEnantioselective synthesisMedicinal chemistryRing (chemistry)PeptideBiochemistryAsymmetric Synthesis and CatalysisCyclopropane Reaction MechanismsSynthesis and Catalytic Reactions