A cyanide‐free platform technology for the synthesis of chiral nitriles by biocatalytic enantioselective dehydration of a wide range of aldoximes is reported. The nitriles were obtained with high enantiomeric excess of >90 % ee (and up to 99 % ee) in many cases, and a “privileged substrate structure” with respect to high enantioselectivity was identified. Furthermore, a surprising phenomenon was observed
Focused Directed Evolution of Pentaerythritol Tetranitrate Reductase by Using Automated Anaerobic Kinetic Screening of Site-Saturated Libraries
作者:Martyn E. Hulley、Helen S. Toogood、Anna Fryszkowska、David Mansell、Gill M. Stephens、John M. Gardiner、Nigel S. Scrutton
DOI:10.1002/cbic.201000527
日期:2010.11.22
Members of the library: Multiple site‐saturated libraries of PETN reductase (shown) were screened for improved kinetic rate against a variety of poorly reduced α,β‐unsaturated activated alkenes by using an anaerobic robotics facility. Two mutants (T26S and W102F) showed a switch in product enantiopreference with substrates (E)‐2‐phenyl‐1‐nitropropene and α‐methyl‐trans‐cinnamaldehyde, respectively
文库成员:通过使用厌氧机器人设备,筛选了多个位点饱和的 PETN 还原酶文库(如图所示),以提高对各种还原程度较差的 α,β-不饱和活化烯烃的动力学速率。两个突变体(T26S 和 W102F)分别显示了与底物 ( E )-2-苯基-1-硝基丙烯和 α-甲基-反式-肉桂醛的产物对映体偏好的转换。
One-pot synthesis of aldoximes from alkenes <i>via</i> Rh-catalysed hydroformylation in an aqueous solvent system
the water-soluble ligand sulfoxantphos were used as the catalyst system, providing high regioselectivities in the initial hydroformylation. A mixture of water and 1-butanol was used as an environmentallybenignsolventsystem, ensuring sufficient contact of the aqueous catalyst phase and the organic substrate phase. The reaction conditions were systematically optimised by Design of Experiments (DoE) using
通过加氢甲酰化和随后的醛中间体与羟胺水溶液的一锅法缩合,成功地实现了直接从烯烃开始的醛糖肟合成。金属配合物Rh(acac)(CO)2和水溶性配体亚砜基磷用作催化剂体系,在初始加氢甲酰化反应中具有很高的区域选择性。将水和1-丁醇的混合物用作对环境无害的溶剂体系,以确保水性催化剂相与有机底物相充分接触。通过使用1-辛烯作为模型底物的实验设计(DoE),系统地优化了反应条件。所需线性末端醛肟的产率为85%((E / Z)-壬醛肟)的区域选择性达到95%。在优化的条件下,其他末端烯烃也成功地转化为相应的线性醛肟,包括可再生底物。通过记录气体消耗来研究反应速率的差异,从而使周转频率(TOF)> 2000 h -1分别观察到4-乙烯基环己烯和苯乙烯。通过使用醛肟脱水酶作为生物催化剂将醛肟肟转化为相应的线性腈,表明醛肟作为平台中间体的潜力很大。因此,整个反应序列允许由烯烃直接合成线性腈,而水是唯一的副产
Laccase-catalysed biotransformation of collismycin derivatives. A novel enzymatic approach for the cleavage of oximes
作者:Javier González-Sabín、Nicolás Ríos-Lombardía、Ignacio García、Natalia M. Vior、Alfredo F. Braña、Carmen Méndez、José A. Salas、Francisco Morís
DOI:10.1039/c5gc02220g
日期:——
An unprecedented and eco-friendly method for the deprotection of oximes with a laccase/tempo system was developed.
一种利用漆酶/TEMPO系统去保护肟的前所未有且环保的方法被开发出来。
Cyanide-free Enantioselective Synthesis of Nitriles: Synthetic Proof of a Biocatalytic Concept and Mechanistic Insights
chiral α‐ and β‐branched nitriles is reported. This process is based on a biocatalytic dehydration of racemic aldoximes by using an aldoxime dehydratase and proceeds with high conversion and excellent enantioselectivity (up to 98 % ee) with water as the only side‐product when starting from a racemic substrate with a high E/Z ratio. Thus, in combination with the facile generation of aldoximes through