Microtubing-Reactor-Assisted Aliphatic C−H Functionalization with HCl as a Hydrogen-Atom-Transfer Catalyst Precursor in Conjunction with an Organic Photoredox Catalyst
作者:Hong-Ping Deng、Quan Zhou、Jie Wu
DOI:10.1002/anie.201804844
日期:2018.9.24
Chlorine radical, which is classically generated by the homolysis of Cl2 under UV irradiation, can abstract a hydrogenatomfrom an unactivated C(sp3)−H bond. We herein demonstrate the use of HCl as an effective hydrogen‐atom‐transfer catalyst precursor activated by an organic acridinium photoredox catalyst under visible‐light irradiation for C−H alkylation and allylation. The key to success relied
A strategically novel protocol for ring-opening functionalization of aryl gem-difluorocyclopropanes (F2CPs), which allows an expedient construction of CF3-containing architectures via visible-light-promoted F-nucleophilic attack manifold, was disclosed. Single electron oxidation of F2CPs was ascribed as the critical step for the success of this transformation by prompting F-nucleophilic attack, as
which otherwise are essentially reluctant towards F‐nucleoplilic addition, now readily participate in this fluoroallylation reaction. Furthermore, this strategy provides an elegant example for the generation, as well as functionalization, of α‐CF3‐substituted benzylic radical intermediates using cheap and readily available starting materials.