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
AbstractDerivatization of alkylated hydroxyaromatics with N‐methyl‐bis(trifluoracetamide) is used for a rapid screening for alkylated hydroxyaromatic compounds in complex mixtures by tandem mass spectrometry. Applications are based on a detailed investigation of the fragmentation reactions of derivatized alkylated phenols, 2,3‐dihydroindenols, indenols, 1,2,3,4‐terrahydronaphtbols and naphthols. As shown by daughter‐ion mass spectra obtained in different field‐free regions of a BEQQ‐instrument, the loss of CF3COOH, CF3CO˙ or CF3COO˙, respectively, is common for the compounds studied and can be used for their detection by means of neutral mass loss scans.