Catalyst-Controlled Regioselectivity in the Synthesis of Branched Conjugated Dienes via Aerobic Oxidative Heck Reactions
作者:Changwu Zheng、Dian Wang、Shannon S. Stahl
DOI:10.1021/ja307371w
日期:2012.10.10
Pd-catalyzed aerobic oxidative coupling of vinylboronic acids and electronically unbiased alkyl olefins provides regioselective access to 1,3-disubstituted conjugateddienes. Catalyst-controlled regioselectivity is achieved by using 2,9-dimethylphenanthroline as a ligand. The observed regioselectivity is opposite to that observed from a traditional (nonoxidative) Heck reaction between a vinyl bromide
Pd 催化的乙烯基硼酸和电子无偏烷基烯烃的有氧氧化偶联提供了对 1,3-二取代共轭二烯的区域选择性访问。催化剂控制的区域选择性是通过使用 2,9-二甲基菲咯啉作为配体来实现的。观察到的区域选择性与从溴乙烯和烯烃之间的传统(非氧化)Heck 反应观察到的相反。DFT 计算研究表明,2,9-二甲基菲咯啉配体的空间效应促进了烯烃内部位置的 CC 键形成。
Transition‐Metal‐Free Deaminative Vinylation of Alkylamines
作者:Jiefeng Hu、Bo Cheng、Xianyu Yang、Teck‐Peng Loh
DOI:10.1002/adsc.201900576
日期:2019.11.5
reactivity is the utilization of pyridinium salt‐activated alkylamines, with a base as a promoter. The transformation exhibits good functional group compatibility, and includes inexpensive primary amine feedstocks and aminoacids. The proposed method can serve as a powerful synthetic method for late‐stage modification of complex compounds. Mechanistic experiments suggest that free radical processes are