Asymmetric Transfer Hydrogenation of 3‐Substituted 2H‐1,4‐Benzoxazines under Tethered Cp*Rh(III)‐Diamine Catalysis with Unexpected Reversal of Enantioselectivity

IF 4.4 2区化学 Q2 CHEMISTRY, APPLIED

Advanced Synthesis & Catalysis Pub Date : 2024-11-12 DOI:10.1002/adsc.202401307

Lijin Xu, Xiaohan Li, Ji Yang, Zhenni He, Wei Huang, Jianbo Yang, Huanrong Li, Qian Shi

引用次数: 0

Abstract

The asymmetric transfer hydrogenation of 3‐substituted 2H‐1,4‐benzoxazines with an azeotropic mixture of HCO2H/NEt3 (5/2) using tethered Cp*Rh(III)‐diamine catalysis has been realized. This process allows access to a broad range of chiral 3,4‐dihydro‐2H‐1,4‐benzoxazines in high yields with up to 99% ee, and tolerates a variety of functional groups. The enantiocontrol is achieved by the judicious choice of catalyst and hydrogen source. This reaction proceeds with unexpected reversal of enantioselectivity, which is attributed to the acidic reaction conditions and the hydrogen bond between the N−H of the rhodium species and the O atom in the substrate.

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系链 Cp*Rh(III)- 二胺催化下 3-取代 2H-1,4-苯并噁嗪的不对称转移加氢反应与意想不到的对映选择性逆转

利用系链 Cp*Rh(III)- 二胺催化，在 HCO2H/NEt3 (5/2) 共沸混合物中实现了 3-取代的 2H-1,4-苯并噁嗪的不对称转移加氢。该工艺可获得多种手性 3,4-二氢-2H-1,4-苯并噁嗪，产量高，ee高达 99%，并可容忍多种官能团。催化剂和氢源的明智选择实现了对映体的控制。该反应在进行过程中出现了意想不到的对映选择性逆转，这归因于酸性反应条件以及铑的 N-H 与底物中 O 原子间的氢键。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Advanced Synthesis & Catalysis 化学-应用化学

CiteScore

9.40

自引率

7.40%

发文量

447

审稿时长

1.8 months

期刊介绍： Advanced Synthesis & Catalysis (ASC) is the leading primary journal in organic, organometallic, and applied chemistry. The high impact of ASC can be attributed to the unique focus of the journal, which publishes exciting new results from academic and industrial labs on efficient, practical, and environmentally friendly organic synthesis. While homogeneous, heterogeneous, organic, and enzyme catalysis are key technologies to achieve green synthesis, significant contributions to the same goal by synthesis design, reaction techniques, flow chemistry, and continuous processing, multiphase catalysis, green solvents, catalyst immobilization, and recycling, separation science, and process development are also featured in ASC. The Aims and Scope can be found in the Notice to Authors or on the first page of the table of contents in every issue.