Mapping the substrate selectivity of new hydrolases using colorimetric screening: lipases from Bacillus thermocatenulatus and Ophiostoma piliferum, esterases from Pseudomonas fluorescens and Streptomyces diastatochromogenes
作者:Andrew Man Fai Liu、Neil A Somers、Romas J Kazlauskas、Terry S Brush、Frank Zocher、Markus M Enzelberger、Uwe T Bornscheuer、Geoff P Horsman、Alessandra Mezzetti、Claudia Schmidt-Dannert、Rolf D Schmid
DOI:10.1016/s0957-4166(01)00072-6
日期:2001.3
screened a general library of 29 substrates and a chiral library of 23 pairs of enantiomers. All four hydrolases catalysed the hydrolysis of unnatural substrates, but the two lipases accepted a broader range of substrates than the two esterases. As expected, the two lipases favoured more hydrophobic substrates, while the two esterases showed a preference for smaller substrates. Several moderately enantioselective
作者:Gregory A. Price、Andrew R. Bogdan、Ana L. Aguirre、Toshiyuki Iwai、Stevan W. Djuric、Michael G. Organ
DOI:10.1039/c6cy00331a
日期:——
Pd-PEPPSI–IPr complex prepared via azide–alkyne cycloaddition is described. The complex was immobilised onto silica gel and applied as a heterogeneouscatalyst in the Negishi reaction. The catalyst was active in both batch and continuous flow operation and was particularly effective for the coupling of heteroaryl chlorides. Long-term continuous flow experiments demonstrated good catalyst activity over
Finding Furfural Hydrogenation Catalysts via Predictive Modelling
作者:Zea Strassberger、Maurice Mooijman、Eelco Ruijter、Albert H. Alberts、Ana G. Maldonado、Romano V. A. Orru、Gadi Rothenberg
DOI:10.1002/adsc.201000308
日期:2010.9.10
studies showed that this transfer hydrogenation follows the so‐called monohydride pathway. Using these data, we built a predictivemodel for 13 of the catalysts, based on 2D and 3D molecular descriptors. We tested and validated the model using the remaining five catalysts (cross‐validation, R2=0.913). Then, with this model, the conversion and selectivity were predicted for four completely new ruthenium‐carbene
我们结合多组分反应、催化性能研究和预测模型来寻找转移氢化催化剂。最初合成并筛选了 18 种钌卡宾配合物,并在糠醛与异丙醇配合物的转移氢化反应中筛选出不同的产率,从 62% 到 >99.9%,没有明显的结构/活性相关性。对照实验证明,卡宾配体在整个反应过程中始终与钌中心保持配位。氘标记研究显示出次级同位素效应(k H : k D = 1.5)。进一步的机理研究表明,这种转移氢化遵循所谓的一氢化物途径。利用这些数据,我们基于 2D 和 3D 分子描述符建立了 13 种催化剂的预测模型。我们使用其余五种催化剂测试并验证了模型(交叉验证,R 2 =0.913)。然后,利用该模型,预测了四种全新的钌卡宾配合物的转化率和选择性。然后合成并测试这四种催化剂。结果与模型预测的误差在 3% 以内,证明了预测模型在催化剂优化中的有效性和价值。
Enantioselectivity of Haloalkane Dehalogenases and its Modulation by Surface Loop Engineering
作者:Zbynek Prokop、Yukari Sato、Jan Brezovsky、Tomas Mozga、Radka Chaloupkova、Tana Koudelakova、Petr Jerabek、Veronika Stepankova、Ryo Natsume、Jan G. E. van Leeuwen、Dick B. Janssen、Jan Florian、Yuji Nagata、Toshiya Senda、Jiri Damborsky
DOI:10.1002/anie.201001753
日期:2010.8.16
In the loop: Engineering of the surfaceloop in haloalkanedehalogenases affects their enantiodiscrimination behavior. The temperature dependence of the enantioselectivity (lnE versus 1/T) of β‐bromoalkanes by haloalkanedehalogenases is reversed (red data points) by deletion of the surfaceloop; the selectivity switches back when an additional single‐point mutation is made. This behavior is not observed
Inductively heated copper wire inside a flow microreactor can serve as a source for a catalytic copper species that promotes 1,3-dipolar cycloadditions of alkynes with in situ formed azides to yield 1,2,3-triazoles. The same setup was used to carry out decarboxylations of 2-alkynoic acids and for the intramolecular C-O coupling of 2′-bromobiphenyl-2-carboxylic acid.
流动微反应器内的感应加热铜线可作为催化铜物质的来源,促进炔烃与原位形成的叠氮化物的 1,3-偶极环加成反应,以产生 1,2,3-三唑。相同的设置用于进行 2-炔酸的脱羧和 2'-溴联苯-2-羧酸的分子内 CO 偶联。