A Strategy for C−H Activation of Pyridines: Direct C-2 Selective Alkenylation of Pyridines by Nickel/Lewis Acid Catalysis
作者:Yoshiaki Nakao、Kyalo Stephen Kanyiva、Tamejiro Hiyama
DOI:10.1021/ja710766j
日期:2008.2.1
The C-2 selective alkenylation of pyridine derivatives is achieved with a catalyst consisting of nickel and Lewis acid. Use of diorganozinc compounds as the Lewis acid catalyst gives C-2 monoalkenylation products, whereas AlMe3 changes the reaction course to afford C-2 dienylated products, which are derived from double insertion of alkynes into the C(2)−H bond. The reaction demonstrates a broad substrate
吡啶衍生物的 C-2 选择性烯基化是通过由镍和路易斯酸组成的催化剂实现的。使用二有机锌化合物作为路易斯酸催化剂产生 C-2 单烯基化产物,而 AlMe3 改变反应过程以提供 C-2 二烯基化产物,其源自炔烃双插入 C(2)-H 键。与之前吡啶直接 CH 官能化的例子相比,该反应展示了广泛的底物范围,并在温和条件下以高化学选择性、区域选择性和立体选择性进行。