手性氢供体催化剂的开发是通过对映选择性氢原子转移(HAT)过程扩展和创新不对称有机催化反应的基础。在此,开发了一种前所未有的手性C 2 -对称芳硫醇催化剂,其衍生自容易获得的对映体乳酸酯。利用这些催化剂,建立了不对称反马尔可夫尼科夫烯烃氢胺化环化反应,提供了多种具有中等到高对映选择性的药学上有趣的3-取代哌啶。设计的对照实验和理论计算的结果合理化了立体控制的起源,并揭示了手性硫醇部分对对映选择性的空间效应。我们相信这些催化剂的简便合成、灵活可调性和有效的对映选择性控制能力将为多功能手性 HAT 催化剂和相关不对称反应的开发提供线索。
Reversing the Regioselectivity of Halofunctionalization Reactions through Cooperative Photoredox and Copper Catalysis
作者:Jeremy D. Griffin、Cortney L. Cavanaugh、David A. Nicewicz
DOI:10.1002/anie.201610722
日期:2017.2.13
Halofunctionalization of alkenes is a classical method for olefin difunctionalization. It gives rise to adducts which are found in many natural products and biologically active molecules, and offers a synthetic handle for further manipulation. Classically, this reaction is performed with an electrophilic halogen source and leads to regioselective formation of the halofunctionalized adducts. Herein
Copper(I)-Catalyzed Oxydifluoroalkylation of Alkenes: A Route to Functionalization of Lactones
作者:Yang Da、Shengnan Han、Xiaoyong Du、Shaodong Liu、Lei Liu、Jie Li
DOI:10.1021/acs.orglett.8b02069
日期:2018.9.7
An efficient copper(I)-catalyzed oxydifluoroalkylation of unsaturated carboxylic acids has been developed under mild reaction conditions. Various α-bromodifluoromethyl substituted heterocycles, esters, amides, and ketones were successfully employed as the CF2 source. This cost-effective copper(I) catalysis provides expedient access to high valued lactones with ample substrate scope, wide functional
Nitrene‐Mediated Enantioselective Intramolecular Olefin Oxyamination to Access Chiral γ‐Aminomethyl‐γ‐Lactones
作者:Xin Nie、Clayton W. Ritter、Marcel Hemming、Sergei I. Ivlev、Xiulan Xie、Shuming Chen、Eric Meggers
DOI:10.1002/anie.202314398
日期:2023.12.18
Nitrene-mediated asymmetric intramolecularolefin difunctionalization is introduced, in which the nitrene intermediate adds in an unprecedented exocyclic fashion and the nucleophile in an endocyclic fashion. This atom-economic strategy affords chiral γ-aminomethyl-γ-lactones in high yields and excellent enantioselectivities and provides access to versatile chiral building blocks.
Direct Catalytic Anti-Markovnikov Hydroetherification of Alkenols
作者:David S. Hamilton、David A. Nicewicz
DOI:10.1021/ja309635w
日期:2012.11.14
A direct intramolecular anti-Markovnikov hydroetherification reaction of alkenols is described. By employing Catalytic quantities of commercially available 9-mesityl-10-methylacridinium perchlorate and 2-phenyl-malononitrile as a redox-cycling source of a H-atom, we report the anti-Markovnikov hydroetherification of alkenes with complete regioselectivity, In addition, we present results demonstrating that this novel catalytic system can be applied to the anti-Markovnikov hydrolactonization of alkenoic acids.
Anti-Markovnikov Hydroamination of Alkenes Catalyzed by an Organic Photoredox System
作者:Tien M. Nguyen、David A. Nicewicz
DOI:10.1021/ja4031616
日期:2013.7.3
Herein we report a metal-free method for the direct anti-Markovnikov hydroamination of unsaturated amines. Irradiation of the amine substrates with visible light in the presence of catalytic quantities of easily synthesized 9-mesityl-10-methylacridinium tetrafluoroborate and thiophenol as a hydrogen-atom donor furnished the nitrogen-containing heterocycles with complete regiocontrol. Two examples of intermolecular anti-Markovnikov alkene hydroamination are also disclosed.