title: Copper-catalyzed three-component synthesis of 3-aminopyrazoles and 4-iminopyrimidines via β-alkynyl-N-sulfonyl ketenimine intermediates.
abstract: 3-Aminopyrazoles and 4-iminopyrimidines were efficiently prepared via copper-catalyzed three-component reactions of butadiynes, sulfonylazides, and hydrazides or imidamides. The reactions were regioselectively approached via the formation of a β-alkynyl-N-sulfonyl ketenimine intermediate which represented a new and effective 1,3-dielectrophilic equivalent in organic synthesis.
authors.affiliation: Department of Chemistry, Zhejiang University , Hangzhou 310027, P. R. China.
authors.forename: Yanpeng
authors.initials: Y
authors.lastname: Xing
authors.forename: Binyu
authors.initials: B
authors.lastname: Cheng
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.forename: Ping
authors.initials: P
authors.lastname: Lu
authors.forename: Yanguang
authors.initials: Y
authors.lastname: Wang