Visible-Light-Initiated Air-Oxygenation of Alkylarenes to Carbonyls Mediated by CarbonTetrabromide in Water
Chunbo Bo, Min Li, Fei Chen*, Jichang Liu, Bin Dai*, Ning Liu*. Chemsuschem, 2023, e202301015.
Abstract
The proposal of synthesizing benzyl skeleton derivatives via direct oxidation of functionalized benzylic C–H bonds has received extensive research attention. Herein, a method was developed to prepare carbonyl compounds via photoinduced aerobic oxidation of ubiquitous benzylic C–H bonds mediated by bromine radicals and tribromomethane radicals. This method employed commercially available CBr4 as a hydrogen atom transfer reagent precursor, air as an oxidant, water as a reaction solvent, and tetra-butylammonium perchlorate (TBAPC) as an additive under mild conditions. A series of substrates bearing different functional groups was converted to aromatic carbonyls in moderate to good yields. Moreover, a low environmental factor (E-factor value = 0.45) showed that the proposed method is ecofriendly and environmentally sustainable.
