Cobalt-Catalyzed Chemo- and Enantioselective Hydrogenation of Conjugated Enynes

Yanhua Hu; Zhenfeng Zhang; Yangang Liu; Wanbin Zhang

doi:10.1002/anie.202106566

Cobalt-Catalyzed Chemo- and Enantioselective Hydrogenation of Conjugated Enynes

Angew Chem Int Ed Engl. 2021 Jul 26;60(31):16989-16993. doi: 10.1002/anie.202106566. Epub 2021 Jun 24.

Authors

Yanhua Hu¹, Zhenfeng Zhang², Yangang Liu^{1

2}, Wanbin Zhang^{1

2}

Affiliations

¹ Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs, Frontier Science Center for Transformative Molecules, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China.
² School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China.

PMID: 34062038
DOI: 10.1002/anie.202106566

Abstract

Asymmetric hydrogenation is one of the most powerful methods for the preparation of single enantiomer compounds. However, the chemo- and enantioselective hydrogenation of the relatively inert unsaturated group in substrates possessing multiple unsaturated bonds remains a challenge. We herein report a protocol for the highly chemo- and enantioselective hydrogenation of conjugated enynes while keeping the alkynyl bond intact. Mechanism studies indicate that the accompanying Zn²⁺ generated from zinc reduction of the Co^II complex plays a critical role to initiate a plausible Co^I /Co^III catalytic cycle. This approach allows for the highly efficient generation of chiral propargylamines (up to 99.9 % ee and 2000 S/C) and further useful chemical transformations.

Keywords: asymmetric hydrogenation; chemoselectivity; cobalt; enynes; propargylamines.

Publication types

Research Support, Non-U.S. Gov't