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。
Kinetic model of asymmetric dehydration of aldoxime catalyzed by immobilized OxdPsp in an organic solvent
Aldoxime dehydratases (Oxds) have received considerable attention recently due to their application in the asymmetric synthesis of nitriles without cyanide by catalyzing the dehydration of aldoxime. However, the low stability of Oxds remains a huge obstacle to achieving high conversions and productivities of hydrophobic substrates. OxdPsp was immobilized on a macroporous adsorption resin (IOP) via
醛肟脱水酶(Oxds)最近因其催化醛肟脱水在无氰化物不对称合成腈中的应用而受到相当大的关注。然而,Oxds的低稳定性仍然是实现疏水底物的高转化率和生产率的巨大障碍。通过ATPS 结合原位固定,将 OxdPsp 固定在大孔吸附树脂 (IOP) 上。IOP催化2-苯基丙醛肟( 1 )脱水制备( S )-2-苯基丙腈(( S ) -2 )成功进行,收率95.7%,ee率94.1%,转化率98.6%。以富集( E )醛肟( E / Z =97/3)为底物,得到富集( S )-腈( ee 94.1% ),符合Gröger对映体优先规则。建立了预测IOP催化脱水的动力学模型,平均偏差为7.6%。IOP 催化的脱水反应遵循包括底物和产物抑制在内的连续机制。开发动力学模型是人工智能在化学工程中应用的关键一步。IOP经过3次回收后,( S ) -2的收率仍达到83.6%,表明IOP的稳定性大大增强,这归因于采用了具有较高lg