研究了使用氧化石墨烯(一种不含金属的非均相碳催化剂)以简便、高效且简单的方案将芳香胺与二卤代烷烃进行 N-杂环化生成氮杂环烷烃和异吲哚啉。该催化剂在温和的温度和大气压反应条件下,在绿色溶剂 H 2 O:EtOH 存在下,在短反应时间内表现出优异的选择性和高产率。具有氧功能的 GO 具有双重用途;它为反应物提供了一个锚定位点,并通过帮助碱解离作为助催化剂引发剂。芳族胺与二卤代烷烃的反应针对催化剂负载、碱、碱负载、反应温度和溶剂进行了优化,在 80 °C、1:2 H 2中产生 84% 的产率O:4 小时内的乙醇溶剂。在以分批补料模式进行反应时观察到产率提高。进一步修改反应方案以采用分批补料策略来维持低浓度的碱并最大限度地减少催化剂的失活。采用分批补料策略,40% 的名义产量提高了 2.3 倍。GO 催化剂很容易通过过滤分离,并显示出显着的可回收性,最多可循环 5 次。通过1 H 和13 C N
Enantiodivergent α-Amino C–H Fluoroalkylation Catalyzed by Engineered Cytochrome P450s
作者:Juner Zhang、Xiongyi Huang、Ruijie K. Zhang、Frances H. Arnold
DOI:10.1021/jacs.9b04344
日期:2019.6.26
engineered cytochrome P450 enzymes to catalyze this abiological reaction under mild conditions with total turnovers (TTN) up to 4070 and enantiomeric excess (ee) up to 99%. The iron-heme catalyst is fully genetically encoded and configurable by directed evolution so that just a few mutations to the enzyme completely inverted product enantioselectivity. These catalysts provide a powerful method for synthesis
Direct Arylation of α‐Amino C(sp
<sup>3</sup>
)‐H Bonds by Convergent Paired Electrolysis
作者:Yueyue Ma、Xiantong Yao、Lei Zhang、Pufan Ni、Ruihua Cheng、Jinxing Ye
DOI:10.1002/anie.201909642
日期:2019.11.11
A metal-free convergent paired electrolysis strategy to synthesize benzylic amines through direct arylation of tertiary amines and benzonitrile derivatives at room temperature has been developed. This TEMPO-mediated electrocatalytic reaction makes full use of both anodic oxidation and cathodic reduction without metals or stoichiometric oxidants, thus showing great potential and advantages for practical
Diverse carbene transferase enzyme catalysts derived from a P450 enzyme
申请人:California Institute of Technology
公开号:US11525123B2
公开(公告)日:2022-12-13
The present disclosure provides cytochrome P450 variants useful for carrying out in vivo and in vitro carbene insertion reactions. Methods for preparing carbene insertion products including cyclopropenes, cyclopropanes, bicyclobutanes, substituted lactones, cyclized compounds, and substituted amines are also described.
DIVERSE CARBENE TRANSFERASE ENZYME CATALYSTS DERIVED FROM A P450 ENZYME
申请人:California Institute of Technology
公开号:US20210292718A1
公开(公告)日:2021-09-23
The present disclosure provides cytochrome P450 variants useful for carrying out in vivo and in vitro carbene insertion reactions. Methods for preparing carbene insertion products including cyclopropenes, cyclopropanes, bicyclobutanes, substituted lactones, cyclized compounds, and substituted amines are also described.
α‐Angelica Lactone Catalyzed Oxidation of Pyrrolidines to Lactams
作者:Siddharth K. Deepake、Manish Kumar、Pawan Kumar、Utpal Das
DOI:10.1002/ejoc.202200712
日期:2022.8.19
An efficient method for the direct oxidation of various N-aryl pyrrolidines to the corresponding lactams using α- angelica lactone as catalyst has been demonstrated. Di-oxygen was employed as the terminal oxidant and oxygen source.