Enantioselective Synthesis of Atropisomers Featuring Pentatomic Heteroaromatics by Pd-Catalyzed C–H Alkynylation
作者:Shuo Zhang、Qi-Jun Yao、Gang Liao、Xin Li、Han Li、Hao-Ming Chen、Xin Hong、Bing-Feng Shi
DOI:10.1021/acscatal.8b04870
日期:2019.3.1
heteroarenes, including pyrroles, thiophenes, benzothiophenes, and benzofurans were compatible with this protocol. Notably, this strategy offers the catalytic asymmetric synthesis of axially chiral 3,3′-bisbenzothiophene with good ee (93% ee). Computational studies revealed the key structural elements that differentiate the rotational barriers of benzothiophene and benzofuran moieties.
由于较低的旋转势垒,具有五元环的阻转异构体的催化不对称结构仍然是一个艰巨的挑战。在本文中,我们描述了Pd催化的对映选择性C–H炔基化反应以合成这种对映异构体。获得了一系列具有一个或什至两个五元环的立体异构C–N或C–C键的阻转异构体(产率高达98%,ee大于99%)。各种五元杂芳烃,包括吡咯,噻吩,苯并噻吩和苯并呋喃均与该方案兼容。值得注意的是,该策略提供了具有良好ee(93%ee)的轴向手性3,3'-双苯并噻吩的催化不对称合成。计算研究揭示了区分苯并噻吩和苯并呋喃部分的旋转壁垒的关键结构要素。