Investigations of alkynylbenziodoxole derivatives for radical alkynylations in photoredox catalysis

Yue Pan; Kunfang Jia; Yali Chen; Yiyun Chen

doi:10.3762/bjoc.14.103

Investigations of alkynylbenziodoxole derivatives for radical alkynylations in photoredox catalysis

Beilstein J Org Chem. 2018 May 28:14:1215-1221. doi: 10.3762/bjoc.14.103. eCollection 2018.

Authors

Yue Pan^{1

2}, Kunfang Jia², Yali Chen¹, Yiyun Chen^{1

2}

Affiliations

¹ Department of Chemistry, Shanghai University, 99 Shangda Road, Shanghai 200444, China.
² State Key Laboratory of Bioorganic and Natural Products Chemistry, Centre for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China.

Abstract

The alkynylbenziodoxole derivatives are recently developed alkynylation reagents in organic synthesis, which demonstrate excellent radical alkynylation reactivity in photoredox catalysis reactions. Herein we report the synthesis of alkynylbenziodoxole derivatives with difluoro, monofluoro, monomethoxy, and dimethoxy substitution on the benziodoxole moiety, and investigated their radical alkynylation reactivity for the first time. A series of mechanistic experiments were conducted to study the radical acceptor and oxidative quencher reactivity of alkynylbenziodoxoles, in which unsubstituted alkynylbenziodoxoles played balancing roles in both processes, while electron-rich benziodoxole derivatives demonstrate synthetic advantages in some cases.

Keywords: acyl radical; alkyl radical; alkynylbenziodoxoles; photoredox catalysis; radical alkynylation.