上海交通大学张万斌团队报道了协同Pd/Cu催化1,5-双手性诱导。相关研究成果发表在2024年3月19日出版的《美国化学会杂志》。

许多研究集中在催化不对称产生单个手性中心或两个相邻的立体中心上。然而，两个不相邻的立体中心的不对称构建具有重要意义，但由于缺乏远程手性诱导模型，因此具有挑战性。

该文中，基于一个C═C键中继策略，研究人员报道了一个协同Pd/Cu催化的1,5-双手性诱导模型。通过简单地改变两种不同构型的手性催化剂的组合，可以不同地获得含有1，5-不相邻立体中心的目标产物的所有四种立体异构体，这些立体中心涉及烯基轴向和中心手性。对照实验和DFT计算揭示了一种新的机制，涉及1，5-氧化加成、反热力学η3-烯丙基钯位移和共轭亲核取代，它们在控制反应性、区域选择性、对映选择性和非对映选择性方面起着关键作用。

预计这个C═C键中继策略可以为具有两个遥远立体中心的结构基序的不对称合成提供通用方案。

附：英文原文

Title: Synergistic Pd/Cu-Catalyzed 1,5-Double Chiral Inductions

Author: Jiacheng Zhang, Yicong Luo, En Zheng, Xiaohong Huo, Shengming Ma, Wanbin Zhang

Issue&Volume: March 19, 2024

Abstract: Much attention has been focused on the catalytic asymmetric creation of single chiral centers or two adjacent stereocenters. However, the asymmetric construction of two nonadjacent stereocenters is of significant importance but is challenging because of the lack of remote chiral induction models. Herein, based on a C═C bond relay strategy, we report a synergistic Pd/Cu-catalyzed 1,5-double chiral induction model. All four stereoisomers of the target products bearing 1,5-nonadjacent stereocenters involving both allenyl axial and central chirality could be obtained divergently by simply changing the combination of two chiral catalysts with different configurations. Control experiments and DFT calculations reveal a novel mechanism involving 1,5-oxidative addition, contra-thermodynamic η3-allyl palladium shift, and conjugate nucleophilic substitution, which play crucial roles in the control of reactivity, regio-, enantio-, and diastereoselectivity. It is expected that this C═C bond relay strategy may provide a general protocol for the asymmetric synthesis of structural motifs bearing two distant stereocenters.

DOI: 10.1021/jacs.4c00497

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.4c00497