在此,介绍了一种钇催化的 2,3-环氧酯和酰胺与胺作为亲核试剂的区域选择性开环反应。该方法具有高区域控制、对映特异性 S N 2 反应途径、广泛的底物范围和温和的反应条件,可提供范围广泛的区域异构纯形式的 α-羟基 β-氨基酯和酰胺。值得注意的是,对 C-3 位的选择性亲核攻击受底物羰基的定向作用控制。
Aminolyse von trans-3-Phenylglycidsäure-Derivaten mit aromatischen Aminen, 4. Mitt
作者:Ait Elker、Jochen Lehmann、Felix Zymalkowski
DOI:10.1002/ardp.19793120106
日期:——
3‐Phenylglycidsäure‐Derivate werden von aromatischen Aminen unterschiedlicher Basizität und Raumerfüllung unter Öffnung des Epoxid‐Ringes stets in 3‐Stellung angegriffen und bilden so 3‐Amino‐2‐hydroxy‐3‐phenyl‐propansäure‐Derivate. Wie die gegenseitige Überführung der Verbindungen 2a→4a→6a→8 zeigt, geschieht dies unabhängig davon, ob es sich um Glycidsäure oder deren Ester, Amid, bzw. Anilid handelt
Development of recyclable chiral macrocyclic metal complexes for asymmetric aminolysis of epoxides: application for the synthesis of an enantiopure oxazolidine ring
作者:Raj Kumar Tak、Manish Kumar、Mohd Nazish、Tushar Kumar Menapara、Rukhsana I. Kureshy、Noor-ul H. Khan
DOI:10.1039/c8nj02960a
日期:——
New recyclable chiral salen complexes Cr(III)1–7 were synthesized from various macrocyclic chiral ligands having multistereogenic chiral centers which work synergistically to give the best results in terms of the enantioselectivity and yield of the products. Among the synthesized complexes, the Cr(III)-4 salen complex efficiently catalyzed the ring opening reaction of various aromatic ester epoxides
Asymmetric Catalytic Syntheses of Pharmaceutically Important<i>β</i>-Amino-<i>α</i>-Hydroxyl Esters by Enantioselective Aminolysis of Methyl Phenylglycidate
作者:Rajkumar Tak、Manish Kumar、Tusharkumar Menapara、Manoj Kumar Choudhary、Rukhsana I. Kureshy、Noor-ul H. Khan
DOI:10.1002/cctc.201601208
日期:2017.1.23
Chiral macrocyclic CrIII salen complexes have been synthesized, characterized, and used as catalysts in the asymmetric aminolysis of aromatic ester epoxides with various anilines to prepare the β‐amino‐α‐hydroxyl esters in very good yield (up to 95 %) along with high diastereo‐ and enantioselectivity (dr>99/1, ee up to 96 %) under the optimized condition particularly with CrIII complex 4, which was
已合成,表征了手性大环Cr III salen配合物,并用作各种苯胺的芳香族酯环氧化物的不对称氨解中的催化剂,制备了β-氨基-α-羟基酯,收率很高(高达95%),而且在优化的条件下,尤其是使用Cr III配合物4时,具有很高的非对映选择性和对映选择性(dr > 99/1,ee高达96%),有效地循环了四次。
Component match in rhodium catalyzed three-component reactions of ethyl diazoacetate, H2O and aryl imines: a highly diastereoselective one-step synthesis of β-aryl isoserine derivatives
作者:Zhenqiu Guo、Taoda Shi、Jun Jiang、Liping Yang、Wenhao Hu
DOI:10.1039/b915013g
日期:——
Water and ethyl diazoacetate were found to be matched components for generating highly reactive nucleophilic oxonium ylide in the presence of a dirhodium acetate catalyst. Simultaneous trapping of the oxonium ylide intermediate with aryl imines gave β-aryl isoserine derivatives with high diastereoselectivity.