Su Lanjun, Sun Huan, Liu Jikai, Wang Chengming
School of Pharmaceutical Sciences, South-Central University for Nationalities, Wuhan 430074, China.
Department of Chemistry, College of Chemistry and Materials Science, Jinan University, Guangzhou 511443, China.
Org Lett. 2021 Jun 18;23(12):4662-4666. doi: 10.1021/acs.orglett.1c01400. Epub 2021 Jun 3.
A quaternary carbon center containing an oxindole motif is constructed via NHC-catalyzed transition-metal and aldehyde-free intermolecular Heck-type alkyl radical addition initiated annulation. This redox-neutral protocol also features a simple procedure, broad substrate scope, good functional group tolerance and could be smoothly amplified to a gram scale. The mechanism study shows that the reaction possibly undergoes two folds of SET processes with an NHC radical cation intermediate involved.
通过氮杂环卡宾（NHC）催化的无过渡金属和醛的分子间Heck型烷基自由基加成引发环化反应，构建了一个含有氧化吲哚基序的季碳中心。这种氧化还原中性的方法还具有操作简单、底物范围广、官能团耐受性好的特点，并且可以顺利放大到克级规模。机理研究表明，该反应可能经历两步单电子转移过程，涉及一个NHC自由基阳离子中间体。
