From Olefination to Alkylation: In-Situ Halogenation of Julia–Kocienski Intermediates Leading to Formal Nucleophilic Iodo- and Bromodifluoromethylation of Carbonyl Compounds
作者:Yanchuan Zhao、Bing Gao、Jinbo Hu
DOI:10.1021/ja301601b
日期:2012.4.4
acceptors. However, direct introduction of -CF(2)I and -CF(2)Br groups through nucleophilic addition is particularly challenging because of the high tendency of decomposition of CF(2)Br(-) and CF(2)I(-) to difluorocarbene. In this work, we have developed a formal nucleophilic iodo- and bromodifluoromethylation for carbonyl compounds. The key strategy of the method is the halogenation of in situ-generated
Radical-Polar Crossover Catalysis with a d<sup>0</sup> Metal Enabled by a Redox-Active Ligand
作者:Joshua T. Gavin、Roman G. Belli、Courtney C. Roberts
DOI:10.1021/jacs.2c09114
日期:2022.11.30
Through use of a redox-active (tris)amido ligand we have accessed this mechanism for use with early transition metals. This mechanism is showcased through enabling product formation for a wide variety of elimination products from α-halo substituted benzylic bromides. The mechanism of this new type of reactivity with Sc is explored, and Hammett analysis reveals an anionic intermediate. The wide functional