Substrate Scope Evaluation of the Enantioselective Reduction of β-Alkyl-β-arylnitroalkenes by Old Yellow Enzymes 1-3 for Organic Synthesis Applications
作者:Mattia Bertolotti、Elisabetta Brenna、Michele Crotti、Francesco G. Gatti、Daniela Monti、Fabio Parmeggiani、Sara Santangelo
DOI:10.1002/cctc.201500958
日期:2016.2
to bioreduction, to define the synthetic potential of this enantioselective reaction in the preparation of chiral fine chemicals. The versatility of the resulting nitroalkanes as chiral building blocks is shown by reducing the nitro group into a primary amine and by converting it into a carboxylic acid moiety by Meyerreaction.
Enantiospecific, Regioselective Cross-Coupling Reactions of Secondary Allylic Boronic Esters
作者:Laetitia Chausset-Boissarie、Kazem Ghozati、Emily LaBine、Jack L.-Y. Chen、Varinder K. Aggarwal、Cathleen M. Crudden
DOI:10.1002/chem.201303683
日期:2013.12.23
enantioselective Suzuki–Miyaura cross‐coupling of chiral, enantioenriched secondaryallylic boronic esters is described (see scheme; DME=dimethoxyethane, Bpin = pinacolboryl, dba = dibenzylideneacetone). Mechanistic studies show that the reactions proceed via γ‐selective transmetalation followed by reductive elimination. The reaction provides the first independent confirmation that the transmetalation of
Entrapment of a chiral cobalt complex within silver: a novel heterogeneous catalyst for asymmetric carboxylation of benzyl bromides with CO<sub>2</sub>
作者:Heng-Pan Yang、Ying-Na Yue、Qi-Long Sun、Qiu Feng、Huan Wang、Jia-Xing Lu
DOI:10.1039/c5cc04554a
日期:——
A novel way to accommodate heterogeneous catalysis, CO2fixation and asymmetric synthesis on one catalyst is reported.
报道了一种新颖的方法,可以在一个催化剂上实现异质催化、CO₂固定和不对称合成。
Directed Evolution of an Enantioselective Lipase with Broad Substrate Scope for Hydrolysis of α-Substituted Esters
作者:Karin Engström、Jonas Nyhlén、Anders G. Sandström、Jan-E. Bäckvall
DOI:10.1021/ja100593j
日期:2010.5.26
Candida antarctica lipase A (CalA) was developed for the hydrolysis of alpha-substituted p-nitrophenyl esters by directed evolution. The E values of this variant for 7 different esters was 45-276, which is a large improvement compared to 2-20 for the wild type. The broad substrate scope of this enzyme variant is of synthetic use, and hydrolysis of the tested substrates proceeded with an enantiomeric
南极假丝酵母脂肪酶 A (CalA) 的一种变体被开发用于通过定向进化水解 α 取代的对硝基苯酯。该变体对 7 种不同酯的 E 值为 45-276,与野生型的 2-20 相比,这是一个很大的改进。这种酶变体的广泛底物范围具有合成用途,测试底物的水解以 95-99% 的对映体过量进行。大多数底物的活性也增加了 30 倍。开发的酶变体显示 (R) 选择性,与对大多数底物具有 (S) 选择性的野生型相比,这是相反的。
The catalytic regio- and enantioselective hydrocarboxylation of alkenes with carbon dioxide is a straightforward strategy to construct enantioenriched α-chiral carboxylic acids but remains a big challenge. Herein we report the first example of catalytic highly enantio- and site-selective remote hydrocarboxylation of a wide range of readily available unactivated alkenes with abundant and renewable CO2
烯烃与二氧化碳的催化区域和对映选择性加氢羧化是构建对映体富集的 α-手性羧酸的简单策略,但仍然是一个巨大的挑战。在此,我们报告了在 SaBOX/Ni 催化剂的温和条件下,利用丰富且可再生的 CO 2对各种容易获得的未活化烯烃进行高度对映和位点选择性远程加氢羧化的催化例子。这一成功的关键是利用手性 SaBOX 配体,它与镍结合,同时控制链行走和羧化的对映选择性。该方法以高产率和区域选择性和对映选择性直接提供一系列带有各种官能团的不同烷基链取代或苯并稠合的 α-手性羧酸。此外,通过从商业起始材料中简明合成抗血小板聚集药物( R )-吲哚布芬,证明了该方法的合成效用。