Copper(0)/PPh<sub>3</sub>-Mediated Bisheteroannulations of <i>o</i>-Nitroalkynes with Methylketoximes Accessing Pyrazo-Fused Pseudoindoxyls
Huanxin Meng, Zhenhua Xu, Zhonghua Qu, Huawen Huang, Guo‐Jun Deng
Abstract
A copper(0)/PPh 3 -mediated cascade bisheteroannulation reaction of o -nitroalkynes with methylketoximes has been developed that provides viable access to a diverse range of pyrazo-fused pseudoindoxyl compounds. Synthetically useful functional groups including sensitive C–I bonds are compatible with this system. Mechanistic studies suggest a reaction cascade involving sequential PPh 3 -mediated deoxygenative cycloisomerization and copper-catalyzed [3 + 2] pyrazo-annulation.
Topics & Concepts
ChemistryCopperStereochemistryCombinatorial chemistryOrganic chemistryCatalytic C–H Functionalization MethodsSynthesis and Catalytic ReactionsCatalytic Alkyne Reactions