Synthetic applications of intramolecular insertion in arylcarbenes. VII. Aryl-substituted benzocycloalkenylidenes

1984 ◽  
Vol 37 (9) ◽  
pp. 1915 ◽  
Author(s):  
WD Crow ◽  
U Engkaninan-Low ◽  
YT Pang
Keyword(s):  
Gas Phase ◽  
Phenyl Ring ◽  
Side Chain ◽  
Electronic Effects ◽  
Carbene Insertion

A series of benzo-fused cyclic carbenes, bearing suitably located alkoxy substituents in the phenyl ring, has been generated in the gas phase and pyrolysed at 250�/0.002-0.40 mm. In all cases, carbene insertion into the adjacent C-H bond (Bamford-Stevens insertion) occurs, either exclusively or predominantly, with up to 35% 1,5 C-H insertion in the alkoxy side chain to form peri-fused tricyclic heterocycles. These results are rationalized in terms of geometrical and electronic effects.

Proton Magnetic Resonance Spectra of Some Amphetamines and Related Compounds and Observations on Rotamer Populations

1971 ◽  
Vol 49 (19) ◽  
pp. 3143-3151 ◽  
Author(s):  
K. Bailey ◽  
A. W. By ◽  
K. C. Graham ◽  
D. Verner
Keyword(s):  
Hydrogen Bonding ◽  
Phenyl Ring ◽  
Proton Magnetic Resonance ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
Side Chain ◽  
Amino Group ◽  
Ortho Position ◽  
Electronic Effects ◽  
Related Compounds

Data from the p.m.r. spectra of β-amino-, β-aminohydrochloride-, β-hydroxy-, and β-nitro-α-phenyl-propanes having methyl or methoxy substituants on the phenyl ring (37 compounds in all) are presented. The α and β protons of the side-chain give a pattern usually analyzable as ABX. The data are discussed in terms of correlations of coupling constants and chemical shifts with electronegativity of the substituent groups, steric and electronic effects, and apparent changes in rotamer populations. Hydrogen-bonding between the amino group of amphetamines and a methoxyl function at the ortho position in the phenyl ring is indicated for the salts but not the free bases.

Gas-phase models of γ turns: Effect of side-chain/backbone interactions investigated by IR/UV spectroscopy and quantum chemistry

2005 ◽  
Vol 123 (8) ◽  
pp. 084301 ◽  
Author(s):  
Wutharath Chin ◽  
François Piuzzi ◽  
Jean-Pierre Dognon ◽  
Iliana Dimicoli ◽  
Michel Mons
Keyword(s):  
Quantum Chemistry ◽  
Gas Phase ◽  
Uv Spectroscopy ◽  
Side Chain ◽  
Phase Models

scholarly journals Diethyl (E)-2,3-bis[(E)-(2-methyl-2-phenylhydrazin-1-ylidene)methyl]but-2-enedioate

2014 ◽  
Vol 70 (6) ◽  
pp. o723-o723
Author(s):  
Peng Liu ◽  
Libin Yuan ◽  
Xiuqing Song ◽  
Hong Yan
Keyword(s):  
Hydrogen Bonds ◽  
Title Compound ◽  
Phenyl Ring ◽  
Side Chain ◽  
Dihedral Angles ◽  
Inversion Symmetry ◽  
Compound C ◽  
Corrugated Sheets ◽  
Major Conformation

The complete molecule of the title compound, C24H28N4O4, is generated by crystallographic inversion symmetry. The ethyl side chain is disordered over two sets of sites in a 0.57 (4):0.43 (4) ratio. The dihedral angles between the methylidene group and the phenyl ring and ester side chain (major conformation) are 7.61 (8) and 86.95 (8)°, respectively. In the crystal, molecules are linkedviaC—H...O hydrogen bonds, forming corrugated sheets lying parallel to (010).

Halogenation Enhances the Photosystem II Inhibitory Activity of 4-Hydroxypyridines: Structure-Activity Relationships and Their Mode of Action

1993 ◽  
Vol 48 (3-4) ◽  
pp. 152-158 ◽  
Author(s):  
Tadao Asami ◽  
Masatoshi Baba ◽  
Hiroyuki Koike ◽  
Yorinao Inoue ◽  
Shigeo Yoshida
Keyword(s):  
Photosystem Ii ◽  
Mode Of Action ◽  
Phenyl Ring ◽  
Pyridine Ring ◽  
Functional Group ◽  
Photosynthetic Electron Transport ◽  
Cross Resistance ◽  
Side Chain ◽  
Structural Resemblance ◽  
Structure Activity

Abstract A range of 4-hydroxypyridines were synthesized and their activity as PET inhibitors were investigated with regard to their structural resemblance to plastoquinone in photosynthetic electron transport (PET). The activity of these compounds was markedly enhanced upon modifying their structures: introduction of halogens into both the 3-and 5-positions of the pyridine ring and additional substitution at the α-position of the side chain at 6-position were effective among others in enhancing the activity. Insertion of a phenyl ring into the side chain at 6-position of the pyridine ring also increased the activity. Substituents on the phenyl ring greatly affected the activity: when substituted with an appropriate functional group, the compounds became 10-to 100-fold more active. The mode of action of both halogenated and non-halogenated 4-hydroxypyridines were investigated by means of thermoluminescence measurements and cross resistance examination against atrazine-resistant thylakoids having mutation in D 1 protein. It was inferred that upon halogenation, 4-hydroxypyridines changed their mode of action from plastoquinone-pool inhibitors to phenol-type inhibitors.

Methylenedioxymethamphetamine-like discriminative stimulus effects of pyrrolidinyl cathinones in rats

2020 ◽  
Vol 34 (7) ◽  
pp. 778-785 ◽  
Author(s):  
Michael B Gatch ◽  
Michael J Forster
Keyword(s):  
Discriminative Stimulus ◽  
Phenyl Ring ◽  
Subjective Effects ◽  
Side Chain ◽  
Club Drugs ◽  
Sprague Dawley ◽  
Discriminative Stimulus Effects ◽  
Sprague Dawley Rats ◽  
Stimulus Effects ◽  
Synthetic Cathinone

Background: Synthetic cathinone derivatives are used as alternatives both for stimulant drugs such as cocaine and methamphetamine and for club drugs such as 3,4-methylenedioxymethamphetamine (MDMA), but little is known about their MDMA-like subjective effects. Methods In order to determine their similarity to MDMA, the discriminative stimulus effects of 10 pyrrolidinyl cathinones (α-pyrrolidinopropiophenone, 4′-methyl-α-pyrrolidinopropiophenone (4′-MePPP), α-pyrrolidinobutiophenone, 3′,4′-methylenedioxy-α-pyrrolidinobutyrophenone (MD-PBP), α-pyrrolidinovalerophenone, 3,4-methylenedioxy-pyrovalerone (MDPV), α-pyrrolidinopentiothiophenone, napthylpyrovalerone (naphyrone), α-pyrrolidinohexiophenone, and 4′-methyl-α-pyrrolidinohexiophenone (4′-MePHP)) were assessed in Sprague–Dawley rats trained to discriminate 1.5 mg/kg racemic ±-MDMA from vehicle. Results: Compounds with no substitutions on the phenyl ring and the thiophene produced 44–67% MDMA-appropriate responding. In contrast, the substituted pyrrolidinyl cathinones produced a range of MDMA-appropriate responding dependent upon the length of the alpha side chain. 4′-MePPP, with a single carbon on the alpha position, produced 99.8% MDMA-appropriate responding, MD-PBP (two carbons) produced 83%, naphyrone (three carbons) produced 71%, MDPV (three carbons) produced, 66%, and 4′-MePHP (four carbons) produced 47%. Conclusions: Many cathinone compounds have discriminative stimulus effects similar to those of MDMA. However, the pyrrolidine substitution appears to reduce serotonergic effects, with a commensurate decrease in MDMA-like effects. Substitutions on the phenyl ring appear to be able to restore MDMA-like responding, but only in compounds with short alpha side chains. These findings agree with earlier findings of increasing dopaminergic effects and stronger reinforcing effects with increasing side chain. Assessment of more compounds is necessary to establish the replicability/robustness of this phenomenon. These findings may be of use in predicting which compounds will have MDMA/club drug-like effects versus psychostimulant-like effects.

On the turn-inducing properties of asparagine: the structuring role of the amide side chain, from isolated model peptides to crystallized proteins

2018 ◽  
Vol 20 (5) ◽  
pp. 3411-3423 ◽  
Author(s):  
S. Habka ◽  
W. Y. Sohn ◽  
V. Vaquero-Vara ◽  
M. Géléoc ◽  
B. Tardivel ◽  
...  
Keyword(s):  
Gas Phase ◽  
Laser Spectroscopy ◽  
Protein Structures ◽  
Side Chain ◽  
Amide Side Chain ◽  
Model Peptides

The anchoring properties of an asparagine (Asn) residue to its local backbone environment in turn model peptides is characterized using gas phase laser spectroscopy and compared to crystallized protein structures.

An intraresidue H-bonding motif in selenocysteine and cysteine, revealed by gas phase laser spectroscopy and quantum chemistry calculations

2020 ◽  
Vol 22 (36) ◽  
pp. 20409-20420 ◽  
Author(s):  
Gildas Goldsztejn ◽  
Venkateswara Rao Mundlapati ◽  
Jérémy Donon ◽  
Benjamin Tardivel ◽  
Eric Gloaguen ◽  
...  
Keyword(s):  
Quantum Chemistry ◽  
Gas Phase ◽  
Laser Spectroscopy ◽  
Side Chain ◽  
Quantum Chemistry Calculations ◽  
Bonding Properties

Models of protein chains containing a seleno-cysteine (Sec) residue have been investigated by gas phase laser spectroscopy in order to document the effect of the H-bonding properties of the SeH group in the folding of the Sec side chain, by comparison with recent data on Ser- and Cys-containing sequences.

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