trans-Arylvinylboronate derivatives are important synthesisblocks in natural products, pharmaceuticals and organic materials. There are only a few reaction conditions that could selectively provide trans-arylvinylboronates by Heck coupling of pinacol vinylboronate and aryl halides. Here we report an efficient and versatile method of palladium catalyzed cross-coupling between pinacol vinylboronate and
Electrochemical Enantioselective Nucleophilic α-C(sp<sup>3</sup>)–H Alkenylation of 2-Acyl Imidazoles
作者:Peng Xiong、Marcel Hemming、Sergei I. Ivlev、Eric Meggers
DOI:10.1021/jacs.2c01686
日期:2022.4.20
catalytic asymmetric indirect electrolysis employing the combination of a redox mediator and a chiral-at-rhodium Lewis acid, which achieves a previously elusive enantioselective nucleophilic α-C(sp3)−H alkenylation of ketones. Specifically, 2-acyl imidazoles react with potassium alkenyl trifluoroborates in high yields (up to 94%) and with exceptional enantioselectivities (27 examples with ≥99% ee) without
将电化学与不对称催化相结合,有望为构建非外消旋手性分子提供一种环境友好且有效的策略。然而,在实践中,手性催化剂在电极和溶液界面的电化学条件下的不稳定性或不相容性带来了重大挑战。在此,我们报道了一种催化不对称间接电解,采用氧化还原介体和手性铑路易斯酸的组合,实现了以前难以捉摸的对映选择性亲核α - C(sp 3 ) -酮的 H 烯基化。具体而言,2-酰基咪唑与链烯基三氟硼酸钾以高产率(高达 94%)和出色的对映选择性(27 个实例,≥99% ee)反应,无需任何额外的化学计量氧化剂(总共 40 个实例)。新的间接电合成可以缩放到克数量,并应用于天然产物隐藻素 A 和组织蛋白酶 K 抑制剂的中间体的直接合成。