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Curt Wentrup 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(42):14942-14951
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Curt W. Bradshaw James J. Lalonde Chi-Huey Wong 《Applied biochemistry and biotechnology》1992,33(1):15-24
This paper describes practical enzymatic procedures for the synthesis of (R) and (S) 1-deuterohexanol, a useful building block for chiral poly isocyanated liquid crystals. Alcohol dehydrogenases from horse liver and Pseudomonas catalyzed the reduction of hexanal with deuterated NAD (NADD) resulting in 50% and 89% yields of (R) and (S) 1-deuterohexanol, respectively. The deuterated cofactor was regenerated in situ by alcohol dehydrogenase catalyzed oxidation of ethanol-d6 or 2-propanol-d8. The (S) alcohol was also synthesized by the horse liver alcohol dehydrogenase reduction of 1-deuterohexanal, which was prepared chemically from hexanal. The yields of the reaction were greatly increased by the use of a biphasic system or with the immobilized enzyme in anhydrous organic solvents. Horse liver alcohol dehydrogenase was stabilized by immobilization on PAN or noncovalent entrapment on XAD resin. 相似文献
67.
Deng W Breneman C Embrechts MJ 《Journal of chemical information and computer sciences》2004,44(2):699-703
Inspired by the concept of knowledge-based scoring functions, a new quantitative structure-activity relationship (QSAR) approach is introduced for scoring protein-ligand interactions. This approach considers that the strength of ligand binding is correlated with the nature of specific ligand/binding site atom pairs in a distance-dependent manner. In this technique, atom pair occurrence and distance-dependent atom pair features are used to generate an interaction score. Scoring and pattern recognition results obtained using Kernel PLS (partial least squares) modeling and a genetic algorithm-based feature selection method are discussed. 相似文献
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Flash pyrolysis of 4-benzylidene-2-phenyl-5(4H)-oxazolone ( 1 ) yields carbonmonoxide, benzene, biphenyl, diphenylacetonitrile, and 2,3-diphenylsuccinonitrile; N-benzoylphenylketenimine is implicated as the primary intermediate. The flash pyrolysis of 4-arylmethylidene-3-methyl-5(4H)-isoxazolones ( 3 ) yields carbon dioxide, acetonitrile, and phenylacetylenes substituted by alkoxy, chloro, dimethylamino, and hydroxy groups, in yields of 45–95%. Arylmethylidenecarbenes are implicated as intermediates. 相似文献
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Rainer Koch Torsten Bruhn Rakesh Naduvile Veedu Curt Wentrup 《Journal of Molecular Structure》2004,686(1-3):31-36
The 13C NMR data of five iminopropadienones R–NCCCO as well as carbon suboxide, C3O2, have been examined theoretically and experimentally. The best theoretical results were obtained using the GIAO/B3LYP/6-31+G**//MP2/6-31G* level of theory, which reproduces the chemical shifts of the iminopropadienone substituents extremely well while underestimating those of the cumulenic carbons by 5–10 ppm. The computationally faster GIAO/HF/6-31+G**//B3LYP/6-31G* level is also adequate. 相似文献
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Ab initio quantum mechanical techniques were used together with PROAIM electron density partitioning and CHELPG electrostatic potential analysis to examine the charge density distribution of model enaminonitrile1 in its planar ground state and in its two rotational transition states. The barrier to rotation about the C-N bond was calculated to be 15.4 and 15.6 kcal/mole for the two rotational transition states at the HF/6-31G** level of theory, and was found to originate from a redistribution of electronic kinetic energy between the amino group and the rest of the molecule in a manner similar to that found for formamide and sulfonamide. Similarly, the C-N bond length and amino group electron population were found to depend upon the C-N torsional angle. Electrostatically derived atomic point charges were also examined at each stationary point using the CHELPG program. CHELPG electrostatic potential results were found to represent the traditional external viewpoint of the charge density consistent with a resonance model, while the results from PROAIM calculations were found to describe the underlying charge density and kinetic energy density redistribution responsible for the rotational barrier. 相似文献