小柯机器人

近日，四川大学Xiaoming Feng、Xiaohua Liu及北京大学深圳研究院的Yun-Dong Wu研究团队，报道了高自旋钴(II)配合物催化的二级脂肪胺的对映选择性形式的乙烯类似物N-H插入。这一研究成果于2021年6月21日发表在国际顶尖学术期刊《美国化学会杂志》上。

该团队报道了一种高γ选择性和对映选择性插入脂肪族或芳香仲胺的N-H键的乙烯基取代α-重氮吡唑酰胺，使用高自旋手性N,N''-二氧化物/钴(II)配合物催化剂。该方法提供了多种有价值的光学活性Z型和E型乙烯基γ-氨基酰胺。计算揭示了四重态钴(II)配合物到二重态Co(II)-卡宾物种的自旋状态变化，实现易Z选择性和对映选择性亲核加成。

据介绍，乙烯基卡宾插入胺的氮-氢(N-H)键可以直接进入α，β不饱和γ-氨基酸衍生物，在控制区域和对映体选择性方面遇到了明显的挑战。

附：英文原文

Title: Enantioselective Formal Vinylogous N–H Insertion of Secondary Aliphatic Amines Catalyzed by a High-Spin Cobalt(II) Complex

Author: Wei Yang, Maoping Pu, Xiaobin Lin, Min Chen, Yanji Song, Xiaohua Liu, Yun-Dong Wu, Xiaoming Feng

Issue&Volume: June 21, 2021

Abstract: Vinylcarbene insertion into the nitrogen–hydrogen (N–H) bond of amines allows direct access to α,β-unsaturated γ-amino acid derivatives, meeting a marked challenge in the control of regio- and enantioselectivities. Here, we report a highly γ-selective and enantioselective insertion into N–H bonds of aliphatic or aromatic secondary amines with vinyl substituted α-diazo pyrazoleamides using a high-spin chiral N,N′-dioxide/cobalt(II) complex catalyst. The method affords a wide variety of valuable optically active Z- and E-type vinyl γ-amino amides. Calculation reveals a spin state change from the quartet cobalt(II) complex to a doublet Co(II)-carbene species for facile Z-selective and enantioselective nucleophilic addition.

DOI: 10.1021/jacs.1c04367

Source: https://pubs.acs.org/doi/10.1021/jacs.1c04367