Enzyme Engineering Based on X-ray Structures and Kinetic Profiling of Substrate Libraries: Alcohol Dehydrogenases for Stereospecific Synthesis of a Broad Range of Chiral Alcohols

ACS Catalysis ◽  
2018 ◽  
Vol 8 (6) ◽  
pp. 5145-5152 ◽  
Author(s):  
Yao Nie ◽  
Shanshan Wang ◽  
Yan Xu ◽  
Shenggan Luo ◽  
Yi-Lei Zhao ◽  
...  
Keyword(s):  
Enzyme Engineering ◽  
Stereospecific Synthesis ◽  
Chiral Alcohols ◽  
Alcohol Dehydrogenases ◽  
X Ray

Stereospecific synthesis of new 5-substituted 6-methyl-4,5-dihydro-2H-pyridazin-3-ones. X-ray assignment study

1984 ◽  
Vol 21 (2) ◽  
pp. 305-310 ◽  
Author(s):  
J. Taoufik ◽  
J. D. Couquelet ◽  
J. M. Couquelet ◽  
A. Carpy
Keyword(s):  
Stereospecific Synthesis ◽  
X Ray

Vitamin-Synthesen mit Carben-Komplexen, III [1]. Stereospezifische Synthese von Alkenylcarben-Komplexen des Chroms / Vitamin Syntheses via Carbene Complexes, III [1]. Stereospecific Synthesis of Alkenylcarbene Chromium Complexes

1983 ◽  
Vol 38 (11) ◽  
pp. 1351-1356 ◽  
Author(s):  
Karl Heinz Dötz ◽  
Werner Kuhn ◽  
Klaus Ackermann
Keyword(s):  
Dihedral Angle ◽  
Stereospecific Synthesis ◽  
Chromium Complexes ◽  
Carbene Complexes ◽  
X Ray

Abstract Addition of lithioalkenes to hexacarbonylchromium followed by alkylation with trimethyloxonium tetrafluoroborate provides a stereospecific route to pentacarbonyl-[alkenyl(methoxy)carbene]chromium complexes. For the E-butenylcarbene complex an approximately orthogonal dihedral angle between the carbene and the alkene plane is established by X-ray analysis.

Stereospecific synthesis, 1H and 13C NMR spectroscopy, and X-ray crystallographic studies of 6,6-dibromo-3α-cyano-2,2-dimethylpenam-(1R)-S-oxide

1991 ◽  
Vol 69 (3) ◽  
pp. 578-583 ◽  
Author(s):  
Claudio J. Salomon ◽  
Oreste A. Mascaretti ◽  
Charles E. Strouse ◽  
G. Punte
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Single Crystal ◽  
Crystal Packing ◽  
Stereospecific Synthesis ◽  
Nmr Studies ◽  
X Ray ◽  
Cell Parameters ◽  
Penicillin Sulfoxide ◽  
Nuclear Magnetic

A stereospecific synthesis of 6,6-dibromo-3α-cyano-2,2-dimethylpenam-(1R)-S-oxide (2) is described. The X-ray single crystal investigation of this compound shows that it crystallizes in the monoclinic system, space group P21, with cell parameters a = 6.194(1), b = 9.363(1), c = 9.869(1) Å, β = 96.55(2)°, V = 568(1) Å3, and two molecules per unit cell. Thestructure was solved, from low temperature data, by direct methods, and refined, by least-squares procedures, to a final R = 3.17%, Rw = 3.38%, for 1221 observed independent reflections. The sulfoxide configuration is R. The thiazolidine presents an envelope shape with the C(3) atom 0.56 Å above the other four members of the ring mean plane. Therefore, it exhibits the conformation with α-CH3 pseudoequatorial and β-CH3 and α-CN both pseudoaxial. This conformation is different from the one reported for other penicillin sulfoxide derivatives. The geometry of the β-lactam ring is typical of the fused bicyclic penam nucleus. The ring is non-planar. The N(4) atom displays a pyramidial arrangement. The examination of crystal packing shows that molecules along a are connected by a short C—H … O contactReported single crystal studies showed two dominant conformations for the thiazolidine ring in the fused bicyclic penam nucleus: the C(3) or 2β-3α substituents both pseudoaxial, as found in 2, and the S(1) or 2β-3α substituents both pseudoequatorial, adopted by most sulfoxides. Neither of these conformations can explain the nuclear Overhauser effect data. A conformation with the substituents C2-β-methyl-C3-α-H and C2-α-methyl-C3-α-CN fully eclipsed is in accordance with the experimental results in the solution. The 1H nuclear magnetic resonance data reflect the influence of the magnetic anisotropy of the CN triple bond on the gem-dimethyl groups, particularly in relation with the geometrical features of the molecule. Comparison of 13C nuclear magnetic resonance chemical shifts for 2 and its parent penicillin sulfide (1) indicates configurationally dependent substituent effects, the magnitude of which can be used for the stereochemical assignment of sulfoxide groups in this series. Key words: penicillin sulfoxide derivatives, di-halogen penicillanates, stereospecific synthesis, NMR studies, absolute configuration determination.

scholarly journals Crystallization and preliminary X-ray analysis of NADP(H)-dependent alcohol dehydrogenases fromSaccharomyces cerevisiaeandRana perezi

2003 ◽  
Vol 59 (2) ◽  
pp. 334-337 ◽  
Author(s):  
Eva Valencia ◽  
Albert Rosell ◽  
Carolina Larroy ◽  
Jaume Farrés ◽  
Josep A. Biosca ◽  
...  
Keyword(s):  
Alcohol Dehydrogenases ◽  
X Ray

Enantioselective ester hydrolyses using Rhizopusnigricans: stereoselective synthesis and absolute stereochemistry of (−)-cis- and (−)-trans-1-hydroxy-4-methyl-1,2,3,4-tetrahydronaphthalene

1985 ◽  
Vol 63 (6) ◽  
pp. 1287-1291 ◽  
Author(s):  
Masaji Kasai ◽  
Herman Ziffer ◽  
J. V. Silverton
Keyword(s):  
Stereoselective Synthesis ◽  
Chiral Alcohols ◽  
Enantioselective Hydrolysis ◽  
Chemical Transformations ◽  
X Ray ◽  
X Ray Crystallography ◽  
Cis And Trans ◽  
Hydrolysis Of ◽  
Absolute Stereochemistry

Enantioselective hydrolysis of racemic acetates of cis- and trans-1-hydroxy-4-methyl-1,2,3,4-tetrahydronaphthalene using Rhizopusnigricans yields chiral alcohols. The absolutestereochemistry of these compounds, and that of a key intermediate in their stereoselective synthesis, r-1-hydroxy-2,t-bromo-4,c-methyl-1,2,3,4-tetrahydronaphthalene, were determined by chemical transformations to 1-oxo-4-methyl-1,2,3,4-tetrahydronaphthalene of known absolute stereochemistry. The relativestereochemistry of the acetate of the key intermediate was established by X-ray crystallography.

Gradient-Enhanced 2D Multinuclear NMR and X-ray Diffraction Studies of Reaction Products of Dimethyltin(IV) Salicylaldoximate with Chiral Alcohols

1998 ◽  
Vol 1998 (10) ◽  
pp. 1467-1472 ◽  
Author(s):  
Abdelkrim Meddour ◽  
Abdeslam Bouhdid ◽  
Marcel Gielen ◽  
Monique Biesemans ◽  
Monique Biesemans ◽  
...  
Keyword(s):  
Chiral Alcohols ◽  
Reaction Products ◽  
X Ray Diffraction ◽  
X Ray ◽  
Multinuclear Nmr
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