title: Copper-catalyzed aerobic oxidative transformation of ketone-derived N-tosyl hydrazones: an entry to alkynes.
abstract: A novel strategy involving Cu-catalyzed oxidative transformation of ketone-derived hydrazone moiety to various synthetic valuable internal alkynes and diynes has been developed. This method features inexpensive metal catalyst, green oxidant, good functional group tolerance, high regioselectivity and readily available starting materials. Oxidative deprotonation reactions were carried out to form internal alkynes and symmetrical diynes. Cross-coupling reactions of hydrazones with halides and terminal alkynes were performed to afford functionalized alkynes and unsymmetrical conjugated diynes. A mechanism proceeding through a Cu-carbene intermediate is proposed for the CC triple bond formation.
authors.affiliation: School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510640 (P.R. China).
authors.forename: Xianwei
authors.initials: X
authors.lastname: Li
authors.forename: Xiaohang
authors.initials: X
authors.lastname: Liu
authors.forename: Huoji
authors.initials: H
authors.lastname: Chen
authors.forename: Wanqing
authors.initials: W
authors.lastname: Wu
authors.forename: Chaorong
authors.initials: C
authors.lastname: Qi
authors.forename: Huanfeng
authors.initials: H
authors.lastname: Jiang
keywords: aerobic oxidation; alkynes; copper-catalyzed; cross-coupling; ketones