Alkene Difunctionalization Triggered by a Stabilized Allenyl Radical: Concomitant Installation of Two Unsaturated C-C Bonds

Yunlong Wei; Hong Zhang; Xinxin Wu; Chen Zhu

doi:10.1002/anie.202106145

Alkene Difunctionalization Triggered by a Stabilized Allenyl Radical: Concomitant Installation of Two Unsaturated C-C Bonds

Angew Chem Int Ed Engl. 2021 Sep 6;60(37):20215-20219. doi: 10.1002/anie.202106145. Epub 2021 Jul 28.

Authors

Yunlong Wei¹, Hong Zhang¹, Xinxin Wu¹, Chen Zhu^{1

2}

Affiliations

¹ Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 199 Ren-Ai Road, Suzhou, Jiangsu, 215123, China.
² Key Laboratory of Synthetic Chemistry of Natural Substances, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China.

PMID: 34151497
DOI: 10.1002/anie.202106145

Abstract

Radical-mediated difunctionalization of alkenes provides a promising approach to introduce one alkenyl or alkynyl group to target compounds. However, simultaneous installation of two unsaturated C-C bonds via alkene difunctionalization remains elusive, attributable to the high instability and transient lifetimes of alkenyl and alkynyl radicals. Herein, we report the photocatalytic 1,2-alkynylalkenylation and 1,2-enynylalkenylation of alkenes for the first time, triggered by the intermolecular addition of a stabilized allenyl radical to an alkene. A portfolio of strategically designed, easily accessible dual-function reagents are applied to a radical docking-migration cascade. The protocol has broad substrate scope and efficiently increases the degree of unsaturation.

Keywords: alkene difunctionalization; alkyne; allenyl radical; radical reactions; rearrangement.

Publication types

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