Enantioselective, Stereoconvergent Resolution Copolymerization of Racemic
<i>cis</i>
‐Internal Epoxides and Anhydrides
作者:Guang‐Hui He、Bai‐Hao Ren、Shi‐Yu Chen、Ye Liu、Xiao‐Bing Lu
DOI:10.1002/anie.202011259
日期:2021.3.8
unreacted epoxide at various conversions. Catalytic activity and copolymer enantioselectivity are strongly influenced by the phenolate ortho‐substituents of the ligand set, as well as the axial linker and its chirality. An enantiopure binaphthol‐linked bimetallic AlIII complex allows stereoconvergent access to the stereoregular semi‐crystalline polyesters and a concomitant kinetic resolution of the
外消旋的顺式-内部环氧化物和酸酐的前所未有的对映选择性拆分共聚反应,是由具有多个手性的双核铝配合物介导的,提供了具有两个连续立体中心的旋光聚酯,以及未反应的底物具有良好的对映选择性。在该拆分共聚中观察到了意外的立体收敛,其中共聚物的对映选择性形成的选择性因子大大超过了在各种转化率下基于未反应的环氧化物的动力学拆分系数。催化活性和共聚物的对映选择性受配体组的酚酸酯邻位取代基,轴向连接基及其手性的影响很大。对映纯联萘酚双金属Al III 配合物可以使立体收敛地接触到有规立构的半结晶聚酯,并伴随着环氧底物的动力学拆分。
Asymmetric oxidation of 1,3-cyclohexadiene catalysed by chloroperoxidase from Caldariomyces fumago
Chloroperoxidase fromCaldariomycesfumago catalyses the oxidation of prochiral 1,3-cyclohexadiene using TBHP as terminal oxidant. The process occurs enantioselectively and furnishes the non-racemic trans diols 1,2- and 1,4-dihydroxycyclohexene, (−)-3 and (+)-4, in good ee and yield.
Chiral diphosphines via 2,3 -sigmatropic rearrangement.Application in asymmetric transition metal catalysis
申请人:PPG-Sipsy S.C.A.
公开号:EP1182205A1
公开(公告)日:2002-02-27
The present invention refers to Chiral diphosphines selected from
a) diphosphines corresponding to the formula
wherein R1 - R4 are each independently selected from substituted and unsubstituted hydrocarbyl groups,
b) diphosphines corresponding to the formula
wherein R1 - R4 are each independently selected from substituted and unsubstituted hydrocarbyl groups with the proviso that if R1 and R2 is phenyl at least one of R3 and R4 is different from phenyl
c) diphosphines corresponding to the formula
wherein R1 - R4 are each independently selected from substituted and unsubstituted hydrocarbyl groups and R5 and R6 are each independently selected from the group consisting of hydrogen, alkyl and residues of protecting groups, whereby R6 and R5 taking together may be an divalent substituent thereby forming a bicyclus, to a method of making same, to a method for preparing a chiral precursor suitable for making the new chiral diphosphines, to transition metal complexes comprising the chiral diphosphines of the present invention, and to the use of either the chiral diphosphines or their transition metal complexes in asymmetric synthesis.