C–H Insertion by Alkylidene Carbenes To Form 1,2,3-Triazines and Anionic [3 + 2] Dipolar Cycloadditions To Form Tetrazoles: Crucial Roles of Stereoelectronic and Steric Effects
作者:Fa-Jie Chen、Yongjia Lin、Man Xu、Yuanzhi Xia、Donald J. Wink、Daesung Lee
DOI:10.1021/acs.orglett.9b04548
日期:2020.1.17
The synthesis of 1,2,3-triazines and bicyclic tetrazoles from α-azido ketones is described. The common intermediate generated from lithiated trimethylsilyldiazomethane and α-azido ketones diverges depending on the steric bulk of the substituents. The formation of 1,2,3-triazines via a C-H insertion of alkylidene carbene to form 3-azidocyclopropene, followed by its rearrangement, is supported by density
描述了由α-叠氮基酮合成1,2,3-三嗪和双环四唑。由锂化的三甲基甲硅烷基重氮甲烷和α-叠氮基酮生成的常见中间体根据取代基的空间体积而不同。密度泛函理论计算支持通过亚烷基卡宾的CH插入形成3-叠氮环丙烯,然后进行重排而形成1,2,3-三嗪。通过锂化螯合促进的锂化重氮基团和叠氮基之间的阴离子[3 + 2]偶极环加成反应,可形成四唑。