Aerobic oxidative desymmetrization of meso-diols with bifunctional amidoiridium catalysts bearing chiral N-sulfonyldiamine ligands
摘要:
Asymmetric aerobic oxidation of a range of meso- and prochiral diols with chiral bifunctional Ir catalysts is described. A high level of chiral discrimination ability of Cp*Ir complexes derived from (S,S)-1,2-diphenylethylenediamine was successfully demonstrated by desymmetrization of secondary benzylic diols such as cis-indan-1,3-diol and cis-1,4-diphenylbutane-1,4-diol, providing the corresponding (R)-hydroxyl ketones with excellent chemo- and enantioselectivities. Enantiotopic group discrimination in oxidation of symmetrical primary 1,4- and 1,5-diols gave rise to chiral lactones with moderate ees under similar aerobic conditions. (C) 2014 Elsevier Ltd. All rights reserved.
Aerobic oxidative desymmetrization of meso-diols with bifunctional amidoiridium catalysts bearing chiral N-sulfonyldiamine ligands
摘要:
Asymmetric aerobic oxidation of a range of meso- and prochiral diols with chiral bifunctional Ir catalysts is described. A high level of chiral discrimination ability of Cp*Ir complexes derived from (S,S)-1,2-diphenylethylenediamine was successfully demonstrated by desymmetrization of secondary benzylic diols such as cis-indan-1,3-diol and cis-1,4-diphenylbutane-1,4-diol, providing the corresponding (R)-hydroxyl ketones with excellent chemo- and enantioselectivities. Enantiotopic group discrimination in oxidation of symmetrical primary 1,4- and 1,5-diols gave rise to chiral lactones with moderate ees under similar aerobic conditions. (C) 2014 Elsevier Ltd. All rights reserved.
The Palladium-Catalyzed Aerobic Kinetic Resolution of Secondary Alcohols: Reaction Development, Scope, and Applications
作者:Davidâ C. Ebner、Jeffreyâ T. Bagdanoff、Ericâ M. Ferreira、Ryanâ M. McFadden、Danielâ D. Caspi、Raissaâ M. Trend、Brianâ M. Stoltz
DOI:10.1002/chem.200902172
日期:2009.12.7
and tert‐butyl alcohol greatly enhances reaction rates, promoting rapid resolutions. The use of chloroform as solvent allows the use of ambient air as the terminal oxidant at 23 °C, resulting in enhanced catalyst selectivity. These improved reaction conditions have permitted the successful kineticresolution of benzylic, allylic, and cyclopropyl secondary alcohols to high enantiomeric excess with good‐to‐excellent
已经开发出第一个钯催化的仲醇对映选择性氧化反应,利用容易获得的二胺(-)-金雀花石作为手性配体,分子氧作为化学计量氧化剂。关于碱基和氢键供体作用的机制见解导致了对原始系统的一些改进。也就是说,碳酸铯和叔丁醇的添加大大提高了反应速率,促进了快速分辨率。使用氯仿作为溶剂允许在 23 °C 下使用环境空气作为终端氧化剂,从而提高催化剂选择性。这些改进的反应条件使得能够以良好至优异的选择性因子成功地将苄基、烯丙基和环丙基仲醇动力学拆分为高对映体过量。该催化剂体系也已应用于内消旋二醇的去对称化,提供高产率的对映体富集的羟基酮。
SYNTHESIS AND APPLICATION OF CHIRAL SUBSTITUTED POLYVINYLPYRROLIDINONES
申请人:Kansas State University Research Foundation
公开号:US20200306737A1
公开(公告)日:2020-10-01
Chiral polyvinylpyrrolidinone (CSPVP), complexes of CSPVP with a core species, such as a metallic nanocluster catalyst, and enantioselective oxidation reactions utilizing such complexes are disclosed. The CSPVP complexes can be used in asymmetric oxidation of diols, enantioselective oxidation of alkenes, and carbon-carbon bond forming reactions, for example. The CSPVP can also be complexed with biomolecules such as proteins, DNA, and RNA, and used as nanocarriers for siRNA or dsRNA delivery.
Asymmetric monobenzoylation reactions of cyclic meso-1,3- and 1,4-diols were catalyzed by a phosphinite derivative of quinidine to afford the corresponding monobenzoylated diol with good yield and enantioselectivity. [reaction: see text]
The Palladium-Catalyzed Oxidative Kinetic Resolution of Secondary Alcohols with Molecular Oxygen
作者:Eric M. Ferreira、Brian M. Stoltz
DOI:10.1021/ja015791z
日期:2001.8.1
The oxidation of secondary alcohols is one of the most common and well-studied reactions in chemistry. Although excellent catalytic enantioselective methods exist for a variety of oxidation processes, such as epoxidation, dihydroxylation, and aziridination, it is surprising that there are relatively few catalytic enantioselective examples of the ubiquitous alcohol oxidation. In connection with a general
new class of pyridine catalyst for asymmetric acylation of sec-alcohols having a conformation switch system in which interconversion between self-complexation and uncomplexation is induced by acylation and deacylation steps, respectively. Kinetic resolution of various sec-alcohols is performed by the asymmetric acylation with isobutyric anhydride using 0.05 to 0.5 mol % catalyst 1a with s values of up
我们已经开发了用于具有构象转换系统的仲醇的不对称酰化的新型吡啶催化剂,在该构象转换系统中,分别通过酰化和脱酰步骤引起自复合和非复合之间的相互转化。各种仲醇的动力学拆分通过异丁酸酐的不对称酰化反应使用0.05至0.5 mol%的催化剂1a(s值最高为30)进行。此外,dl-二醇也以相似的方式以良好的选择性拆分。此外,在存在0.5-5 mol%催化剂的情况下,内消旋-1,X-二醇(X = 2-6)不对称脱对称1a。在1 H NMR测量,X射线结构分析以及AM1和DFT计算的基础上,提出了反应机理的工作模型,其中构象转换系统由吡啶环与环之间的分子内阳离子-π相互作用控制。硫羰基将在获得良好的选择性和高催化活性方面起关键作用。