Enantioselective Carbon-Carbon Bond Cleavage for Biaryl Atropisomers Synthesis
Enantioselective Carbon-Carbon Bond Cleavage for Biaryl Atropisomers Synthesis
复制标题
用于联芳基阻转异构体合成的对映选择性碳-碳键断裂
DOI：
10.1016/j.chempr.2019.04.008
复制
发表时间：
2019-07-11
期刊：
影响因子：
23.5
通讯作者：
Gu, Zhenhua
中科院分区：
文献类型：
--
作者：
Deng, Ruixian;Xi, Junwei;Gu, Zhenhua
发展对映选择性的碳-碳键和碳-杂原子键的新合成策略是现代有机化学的支柱之一。虽然在中心手性结构方面已经取得了重大进展，但轴向手性的催化不对称结构仍在开发中。此外，通过碳-碳和碳-杂原子键断裂构建的轴向手性分子是极其有限的。在这里，我们报告了一个不对称合成联芳基阻转异构体通过钯催化的化学选择性碳-碳裂解的9-芳基-9H-芴-9-醇。该反应具有较宽的底物范围，并以高产率和对映选择性生成阻转异构体。底物中联芳基骨架上两个邻位取代基之间的空间排斥作用产生的扭转应变大大加速了开环反应。高对映体控制取决于新的TADDOL基亚磷酰胺作为配体的发展。这些发现为通过不对称碳-碳裂解开发新型合成方法建立了新平台。
Development of new synthetic strategies for enantioselective carbon-carbon and carbon-heteroatom bond formation is one of the pillars of modern organic chemistry. Whereas significant advances have been achieved in center chirality construction, catalytically asymmetric construction of axial chirality is still under development. Moreover, axially chiral molecules constructed through carbon-carbon and carbon-heteroatom bond cleavage are extremely limited. Here, we report an asymmetric synthesis of biaryl atropisomers via palladium-catalyzed chemoselective carbon-carbon cleavage of 9-aryl-9H-fluoren-9-ols. The reaction demonstrated broad substrate scope and produced the atropisomers in high yields and enantioselectivity. The ring-opening reactivity was considerably accelerated by the torsional strain created by the steric repulsion between two ortho-substituents of the biaryl skeleton in the substrates. The high enantiocontrol hinges on the evolvement of a new TADDOL-based phosphoramidite as ligand. These findings set up a new platform for the development of novel synthetic methods via asymmetric carbon-carbon cleavage.