Oxidative Trifluoroacetoxylation of 1°, 2°, and 3° Benzylic C(sp<sup>3</sup>)–H Bond Donors Using <i>N</i>-Trifluoroacetoxyquinuclidinium Salts under Photoredox Catalysis
作者:Michael Hitt、Andrei N. Vedernikov
DOI:10.1021/acs.orglett.2c02946
日期:2022.10.28
trifluoroacetate was prepared in situ from quinuclidine N-oxide and (CF3CO)2O. Except for some electron-poor substrates, this reagent allows for the high-yielding oxidative trifluoroacetoxylation of 1°, 2°, and 3° benzylic C–H bonds under photocatalytic conditions. The trifluoroacetoxylation of an ibuprofen methyl ester allowed the selective functionalization of a 2° benzylic C–H bond. For alkylbenzenes, hydrogen-atom
N-三氟乙酰氧基奎宁环三氟乙酸盐由奎宁环N-氧化物和 (CF 3 CO) 2 O原位制备。除了一些缺电子底物外,该试剂允许 1°、2° 和 3° 的高产率氧化三氟乙酰氧基化光催化条件下的苄基 C-H 键。布洛芬甲酯的三氟乙酰氧基化允许 2° 苄基 C-H 键的选择性官能化。对于烷基苯,氢原子从苄基 C-H 键转移到奎宁环阳离子自由基被认为是决定反应产物的步骤。