Center of Chemistry for Frontier Technologies, Department of Chemistry, Zhejiang University, Hangzhou, 310027, China.
College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou, 450001, China.
Angew Chem Int Ed Engl. 2021 Oct 18;60(43):23187-23192. doi: 10.1002/anie.202108853. Epub 2021 Sep 24.
An unprecedented enantioselective synthesis of spiro-γ-lactams via a sequential C-H olefination/asymmetric [4+1] spirocyclization under a simple Co /chiral spiro phosphoric acid (SPA) binary system is reported. A range of biologically important spiro-γ-lactams are obtained with high levels of enantioselectivity (up to 98 % ee). The concise, asymmetric synthesis of an aldose reductase inhibitor was successfully achieved. Notably, contrast to previous reports that relied on the use of cyclopentadienyl or its derivatives (achiral Cp*, Cp , or chiral Cp ) ligated Co complexes requiring tedious steps to prepare, cheap and commercially available cobalt(II) acetate tetrahydrate was used as an efficient precatalyst.
报道了一种通过简单的 Co/手性螺环磷酸（SPA）双体系进行连续 C-H 烯丙基化/不对称 [4+1] 螺环化反应，实现前所未有的对映选择性 spiro-γ-内酰胺的合成。通过这种方法可以获得一系列具有高对映选择性（高达 98%ee）的生物重要的 spiro-γ-内酰胺。成功实现了醛糖还原酶抑制剂的简洁、不对称合成。值得注意的是，与之前依赖于使用环戊二烯基或其衍生物（无手性 Cp*、Cp 或手性 Cp）配位的 Co 配合物的报道形成对比，所需的繁琐步骤来制备，廉价且可商购的二水合乙酸钴(II)被用作有效的前催化剂。
