Highly Selective Hydrolytic Kinetic Resolution of Terminal Epoxides Catalyzed by Chiral (salen)Co<sup>III</sup> Complexes. Practical Synthesis of Enantioenriched Terminal Epoxides and 1,2-Diols
作者:Scott E. Schaus、Bridget D. Brandes、Jay F. Larrow、Makoto Tokunaga、Karl B. Hansen、Alexandra E. Gould、Michael E. Furrow、Eric N. Jacobsen
DOI:10.1021/ja016737l
日期:2002.2.1
The hydrolytickineticresolution (HKR) of terminal epoxides catalyzed by chiral (salen)Co(III) complex 1 x OAc affords both recovered unreacted epoxide and 1,2-diol product in highly enantioenriched form. As such, the HKR provides general access to useful, highly enantioenriched chiral building blocks that are otherwise difficult to access, from inexpensive racemic materials. The reaction has several
Scope and Mechanism of the Pt-Catalyzed Enantioselective Diboration of Monosubstituted Alkenes
作者:John R. Coombs、Fredrik Haeffner、Laura T. Kliman、James P. Morken
DOI:10.1021/ja4041016
日期:2013.7.31
The Pt-catalyzed enantioselective diboration of terminal alkenes can be accomplished in an enantioselective fashion in the presence of chiral phosphonite ligands. Optimal procedures and the substrate scope of this transformation are fully investigated. Reaction progress kinetic analysis and kinetic isotope effects suggest that the stereodefining step in the catalytic cycle is olefin migratory insertion
Hydrolytic Kinetic Resolution of Epoxides Catalyzed by Chromium(III)-endo,endo-2,5-diaminonorbornane-salen [Cr(III)-DIANANE-salen] Complexes. Improved Activity, Low Catalyst Loading
作者:Albrecht Berkessel、Erkan Ertürk
DOI:10.1002/adsc.200606181
日期:2006.12
The hydrolytickineticresolution (HKR) of terminal epoxides, using chiral chromium(III)-salen catalysts based on DIANANE (endo,endo-2,5-diaminonorbornane), was studied. A broad substrate scope was found for the chromium(III)-DIANANE catalysts, and very low loadings (down to 0.05 mol %) were needed to achieve high enantiomeric purities of both the remaining epoxides and the product diols (up to >99 %
Highly Enantioselective Iron-Catalyzed <i>cis</i>
-Dihydroxylation of Alkenes with Hydrogen Peroxide Oxidant via an Fe<sup>III</sup>
-OOH Reactive Intermediate
作者:Chao Zang、Yungen Liu、Zhen-Jiang Xu、Chun-Wai Tse、Xiangguo Guan、Jinhu Wei、Jie-Sheng Huang、Chi-Ming Che
DOI:10.1002/anie.201603410
日期:2016.8.22
catalysts for highly enantioselective asymmetric cis‐dihydroxylation (AD) of alkenes with broad substrate scope remains a challenge. By employing [FeII(L)(OTf)2] (L=N,N′‐dimethyl‐N,N′‐bis(2‐methyl‐8‐quinolyl)‐cyclohexane‐1,2‐diamine) as a catalyst, cis‐diols in up to 99.8 % ee with 85 % isolated yield have been achieved in AD of alkenes with H2O2 as an oxidant and alkenes in a limiting amount. This “[FeII(L)(OTf)2]+H2O2”
开发具有良好底物范围的烯烃的高对映选择性不对称顺二羟基化(AD)的环境友好型催化剂仍然是一个挑战。通过使用[Fe II(L)(OTf)2 ](L = N,N'-二甲基-N,N'-双(2-甲基-8-喹啉基)-环己烷-1,2-二胺)作为催化剂,在以H 2 O 2为氧化剂的烯烃和数量有限的烯烃的AD中,已实现了高达99.8%ee的顺式二醇和85%的分离产率。该“ [Fe II(L)(OTf)2 ] + H 2 O 2”方法适用于(E)-烯烃和末端烯烃(24个实例,ee大于80%,最大1 g)。机理研究包括18种O-标记,UV / Vis,EPR,ESI-MS分析和DFT计算,为手性Fe III- OOH活性物种参与两个C-O键的对映选择性形成提供了证据。
The use of chiral alcohols to form the Lewis acid–base *RO− → bis(pinacolato)diboron adduct, in situ, provides an opportunity to induce asymmetry in the organocatalytic diboration of alkenes and complements the well established transition metal-mediated enantioselective diboration.