ChemInform Abstract: NMR and X-Ray Evidence for the Chair Conformation of Six-Membered Rings Attached Diequatorially to Five-Coordinate Phosphorus. Implications for Reported Transition-State Analogues of Nucleoside Cyclic 3′,5′-Monophosphate Hydrolysis

ChemInform ◽  
2010 ◽  
Vol 24 (39) ◽  
pp. no-no
Author(s):  
Y. HUANG ◽  
A. E. SOPCHIK ◽  
A. M. ARIF ◽  
W. G. BENTRUDE
Keyword(s):  
Transition State ◽  
Chair Conformation ◽  
X Ray ◽  
Transition State Analogues

Crystal structure determination of the conformation of two bicyclo[3.3.1]nonan-ones

1985 ◽  
Vol 63 (6) ◽  
pp. 1166-1169 ◽  
Author(s):  
John F. Richardson ◽  
Ted S. Sorensen
Keyword(s):  
Crystal Structure ◽  
Direct Methods ◽  
Chair Conformation ◽  
Molecular Structures ◽  
Boat Conformation ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Final Agreement

The molecular structures of exo-7-methylbicyclo[3.3.1]nonan-3-one, 3, and the endo-7-methyl isomer, 4, have been determined using X-ray-diffraction techniques. Compound 3 crystallizes in the space group [Formula: see text] with a = 15.115(1), c = 7.677(2) Å, and Z = 8 while 4 crystallizes in the space group P21 with a = 6.446(1), b = 7.831(1), c = 8.414(2) Å, β = 94.42(2)°, and Z = 2. The structures were solved by direct methods and refined to final agreement factors of R = 0.041 and R = 0.034 for 3 and 4 respectively. Compound 3 exists in a chair–chair conformation and there is no significant flattening of the chair rings. However, in 4, the non-ketone ring is forced into a boat conformation. These results are significant in interpreting what conformations may be present in the related sp2-hybridized carbocations.

scholarly journals Organofluorine chemistry: Difluoromethylene motifs spaced 1,3 to each other imparts facial polarity to a cyclohexane ring

2016 ◽  
Vol 12 ◽  
pp. 2823-2827 ◽  
Author(s):  
Mathew J Jones ◽  
Ricardo Callejo ◽  
Alexandra M Z Slawin ◽  
Michael Bühl ◽  
David O'Hagan
Keyword(s):  
Solid State ◽  
Design Strategy ◽  
Chair Conformation ◽  
Axial Orientation ◽  
Solution Nmr ◽  
Cyclohexane Ring ◽  
X Ray

2,2-Dimethyl-5-phenyl-1,1,3,3-tetrafluororocyclohexane has been prepared and characterised as an example of a facially polarised cyclohexane containing 1,3 related CF2 groups. The dipolar nature of the ring arises from the axial orientation of two of the C–F bonds pointing in the same direction, and set by the chair conformation of the cyclohexane. This electrostatic profile is revealed experimentally both in the solid-state (X-ray) packing of the rings and by solution (NMR) in different solvents. A computationally derived electrostatic profile of this compound is consistent with a more electronegative and a more electropositive face of the cyclohexane ring. This placing of CF2 groups 1,3 to each other in a cyclohexane ring is introduced as a new design strategy which could be applicable to the preparation of polar hydrophobic cyclohexane motifs.

scholarly journals New human renin inhibitory peptides. Angiotensinogen transition-state analogues containing novel Leu-Val replacement and a retro-inverso amide bond.

1988 ◽  
Vol 36 (6) ◽  
pp. 2278-2281 ◽  
Author(s):  
Kinji Iizuka ◽  
Tetsuhide Kamijo ◽  
Hiromu Harada ◽  
Kenji Akahane ◽  
Tetsuhiro Kubota ◽  
...  
Keyword(s):  
Transition State ◽  
Amide Bond ◽  
Inhibitory Peptides ◽  
Transition State Analogues ◽  
Human Renin

scholarly journals Tight Binding of Transition-State Analogues to a Peptidyl-Aminoacyl-L/D-Isomerase from Frog Skin

ChemBioChem ◽  
2011 ◽  
Vol 12 (13) ◽  
pp. 1996-2000 ◽  
Author(s):  
Verena Gehmayr ◽  
Christa Mollay ◽  
Lorenz Reith ◽  
Norbert Müller ◽  
Alexander Jilek
Keyword(s):  
Transition State ◽  
Frog Skin ◽  
Tight Binding ◽  
Transition State Analogues

scholarly journals Polyvalent transition-state analogues of sialyl substrates strongly inhibit bacterial sialidases.

2020 ◽  
Author(s):  
coralie assailly ◽  
clarisse bridot ◽  
amélie saumonneau ◽  
paul lottin ◽  
Benoit Roubinet ◽  
...  
Keyword(s):  
Transition State ◽  
Important Class ◽  
Inhibitory Potency ◽  
Polymeric Scaffolds ◽  
Transition State Analogues

<div>Conjugation of the transitionstate-cation analogue DANA to polymeric scaffolds led to highly potent inhibitors of bacterial sialidases. Each clustered DANA on the polymers saw its inhibitory potency for S. pneumoniae or B. thetaiotaomicron sialidases improved by more than four orders of magnitude. This extends the multivalent concept to this important class of enzymes.</div><div><br></div>

scholarly journals Transition-State Analogues of Phenylethanolamine N-Methyltransferase

2020 ◽  
Vol 142 (33) ◽  
pp. 14222-14233 ◽  
Author(s):  
Niusha Mahmoodi ◽  
Rajesh K. Harijan ◽  
Vern L. Schramm
Keyword(s):  
Transition State ◽  
Transition State Analogues
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