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Redox‐Active Reagents for Photocatalytic Generation of the OCF 3 Radical and (Hetero)Aryl C−H Trifluoromethoxylation
Author(s) -
Zheng Weijia,
Lee Johnny W.,
MoralesRivera Cristian A.,
Liu Peng,
Ngai MingYu
Publication year - 2018
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201808495
Subject(s) - reagent , chemistry , radical , photoredox catalysis , photochemistry , cationic polymerization , catalysis , photocatalysis , aryl , deprotonation , radical ion , redox , electron transfer , aryl radical , intermolecular force , combinatorial chemistry , organic chemistry , molecule , alkyl , ion
The trifluoromethoxy (OCF 3 ) radical is of great importance in organic chemistry. Yet, the catalytic and selective generation of this radical at room temperature and pressure remains a longstanding challenge. Herein, the design and development of a redox‐active cationic reagent ( 1 ) that enables the formation of the OCF 3 radical in a controllable, selective, and catalytic fashion under visible‐light photocatalytic conditions is reported. More importantly, the reagent allows catalytic, intermolecular C−H trifluoromethoxylation of a broad array of (hetero)arenes and biorelevant compounds. Experimental and computational studies suggest single electron transfer (SET) from excited photoredox catalysts to 1 resulting in exclusive liberation of the OCF 3 radical. Addition of this radical to (hetero)arenes gives trifluoromethoxylated cyclohexadienyl radicals that are oxidized and deprotonated to afford the products of trifluoromethoxylation.