Enantioselective Synthesis of Axially Chiral Benzothiophene/Benzofuran‐Fused Biaryls by N‐Heterocyclic Carbene Catalyzed Arene Formation
作者:Chun‐Lin Zhang、Yuan‐Yuan Gao、Hai‐Ying Wang、Bang‐An Zhou、Song Ye
DOI:10.1002/anie.202103415
日期:2021.6.14
Axially chiral biaryl scaffolds are prevalent in natural products, chiral ligands, and organocatalysts. However, N-heterocyclic carbene (NHC) catalyzed de novo construction of an aromatic ring with concomitant axial chirality induction for the synthesis of biaryl atropisomers is far less developed, and the efficient synthesis of axially chiral tetra-ortho-substituted biaryls remains an unsolved problem
轴向手性联芳支架在天然产物、手性配体和有机催化剂中很普遍。然而,N-杂环卡宾(NHC)催化从头构建芳环并伴随轴向手性诱导合成联芳基阻转异构体的进展还很有限,并且轴向手性四邻位异构体的有效合成-取代的联芳基在 NHC 催化下仍然是一个未解决的问题。这里报道的是 NHC 催化从烯醛和 2-苄基-苯并噻吩/苯并呋喃-3-甲醛通过 [2+4] 环化、脱羧和氧化芳构化级联反应从头合成轴向手性苯并噻吩/苯并呋喃稠合的联芳基化合物。到轴向手性转换。所开发的方法提供了以高对映选择性获得新型轴向手性苯并噻吩/苯并呋喃稠合联芳基化合物的有效且通用的途径,并且适用于合成四邻位取代的联芳基化合物。