Cyclometallation Reactions in the Fe(dprpe)2 System [dprpe = 1,2-Bis(dipropylphosphino)ethane].

1999 ◽  
Vol 52 (11) ◽  
pp. 1005 ◽  
Author(s):  
Murray V. Baker ◽  
Leslie D. Field
Keyword(s):  
Methyl Group ◽  
Thermal Elimination ◽  
Intramolecular Activation

Thermal elimination of methane from cis-FeH(CH3)(dprpe)2 [dprpe = 1,2-bis(dipropylphosphino)ethane] or photochemical elimination of dihydrogen from FeH2(dprpe)2 leads to the formation of three cyclometallation products. The products are believed to arise via a pathway in which the coordinatively unsaturated intermediate Fe(dprpe)2 undergoes intramolecular activation of a C–H bond of a dprpe methyl group. 1H and 31P n.m.r. spectroscopy were used to characterize the products and explore the reactions leading to their formation.

Use of [13C-methyl]Tropinone to follow the fate of the methyl group during calystegine formation in root cultures of Solanum dulcamara (Solanaceae)

Planta Medica ◽  
2008 ◽  
Vol 74 (09) ◽  
Author(s):  
TA Bartholomeusz ◽  
R Molinié ◽  
A Roscher ◽  
AC Freydank ◽  
B Dräger ◽  
...  
Keyword(s):  
Root Cultures ◽  
Solanum Dulcamara ◽  
Methyl Group

STEROIDSTRUKTUR UND LEBERTOXIZITÄT

1967 ◽  
Vol 54 (1) ◽  
pp. 73-84 ◽  
Author(s):  
H. L. Krüskemper ◽  
G. Noell
Keyword(s):  
Alkaline Phosphatase ◽  
Liver Function ◽  
Blood Coagulation ◽  
Electrophoretic Pattern ◽  
Coagulation Factors ◽  
Blood Coagulation Factors ◽  
Methyl Group ◽  
Liver Functions ◽  
Male Subjects ◽  
Androstane Derivatives

ABSTRACT In male subjects investigations have been carried out regarding the effect of C1- and C17-methylated androstane derivatives (20 mg per day, orally, two weeks) on liver functions (parameters: activities of GPT, GOT, alkaline phosphatase and cholinesterase in serum; electrophoretic pattern; blood coagulation factors V, VII, X and prothrombin; BSP-retention). In addition to the well known hepatotropic action of 17α-alkylated C-19-steroids a quasi-axial 1α-methyl configuration (in 1α-methylandrost-2-en-17β-ol) definitely increased BSP-retention and several coagulation factors. These steroid effects decreased gradually when a methyl group was introduced in C1 equatorially (1-methylandrost-1-en-17β-ol-3-one) or quasi-equatorially (1β-methylandrost-2-en-17β-ol), the latter compound completely lacking from any influence on parameters of liver function under investigation.

A Reinvestigation of the Deceptively Simple Reaction of Toluene with ●OH, and the Fate of the Benzyl Radical. I. a Combined Thermodynamic and Kinetic Study on the Competition Between ●OH Addition and Hydrogen Abstraction Reactions.

2019 ◽  
Author(s):  
Zoi Salta ◽  
Agnie M. Kosmas ◽  
Marc E. Segovia ◽  
Martina Kieninger ◽  
Oscar Ventura ◽  
...  
Keyword(s):  
Density Functional ◽  
Room Temperature ◽  
Hydrogen Abstraction ◽  
Reaction Rates ◽  
Composite Model ◽  
Alternative Mechanism ◽  
Radical Intermediate ◽  
Experimental Conditions ◽  
Methyl Group ◽  
Benzyl Radical

This work reports density functional and composite model chemistry calculations performed on the reactions of toluene with the hydroxyl radical. Both experimentally observed H-abstraction from the methyl group and possible additions to the phenyl ring were investigated. Reaction enthalpies and heights of the barriers suggest that H-abstraction is more favorable than ●OH addition to the ring. The calculated reaction rates at room temperature and the radical-intermediate product fractions support this view. This is somehow contradictory with the fact that, under most experimental conditions, cresols are observed in a larger concentration than benzaldehyde. Since the accepted mechanism for benzaldehyde formation involves H-abstraction, a contradiction arises that begs for an explanation. In this first part of our work we give the evidences that support the preference of hydrogen abstraction over ●OH addition and suggest an alternative mechanism which shows that cresols can actually arise also from the former reaction and not only from the latter.

A Reinvestigation of the Deceptively Simple Reaction of Toluene with ●OH, and the Fate of the Benzyl Radical. I. a Combined Thermodynamic and Kinetic Study on the Competition Between ●OH Addition and Hydrogen Abstraction Reactions.

2019 ◽  
Author(s):  
Zoi Salta ◽  
Agnie M. Kosmas ◽  
Marc E. Segovia ◽  
Martina Kieninger ◽  
Oscar Ventura ◽  
...  
Keyword(s):  
Density Functional ◽  
Room Temperature ◽  
Hydrogen Abstraction ◽  
Reaction Rates ◽  
Composite Model ◽  
Alternative Mechanism ◽  
Radical Intermediate ◽  
Experimental Conditions ◽  
Methyl Group ◽  
Benzyl Radical

This work reports density functional and composite model chemistry calculations performed on the reactions of toluene with the hydroxyl radical. Both experimentally observed H-abstraction from the methyl group and possible additions to the phenyl ring were investigated. Reaction enthalpies and heights of the barriers suggest that H-abstraction is more favorable than ●OH addition to the ring. The calculated reaction rates at room temperature and the radical-intermediate product fractions support this view. This is somehow contradictory with the fact that, under most experimental conditions, cresols are observed in a larger concentration than benzaldehyde. Since the accepted mechanism for benzaldehyde formation involves H-abstraction, a contradiction arises that begs for an explanation. In this first part of our work we give the evidences that support the preference of hydrogen abstraction over ●OH addition and suggest an alternative mechanism which shows that cresols can actually arise also from the former reaction and not only from the latter.

New Amine and Aromatic Substituted Analogues of Phencyclidine: Synthesis and Determination of Acute and Chronic Pain Activities

2019 ◽  
Vol 22 (8) ◽  
pp. 570-576
Author(s):  
Maryam Shokrollahi ◽  
Marjaneh Samadizadeh ◽  
Mohsen Khalili ◽  
Seyed A. Sobhanian ◽  
Abbas Ahmadi
Keyword(s):  
Nmda Receptors ◽  
Phenyl Ring ◽  
Piperidine Ring ◽  
Methyl Group ◽  
Physiological Properties ◽  
Antinociceptive Effects ◽  
The Central Nervous System ◽  
Analgesic Activities ◽  
Compound Ii ◽  
New Compounds

Background: Phencyclidine (PCP, I) is a synthetic drug with remarkable physiological properties. PCP and its analogues exert many pharmacological activities and interact with some neurotransmitter systems in the central nervous system like particular affinity for PCP sites in NMDA receptors or dopamine uptake blocking or even both. Aim and Objective: The following research, methyl group with electron-donating and dipole moment characters was added in different positions of phenyl ring along with the substitution of benzylamine (with many pharmacological effects) instead of piperidine ring of I to produce new compounds (II-V) of this family with more analgesic activities. Materials and Methods: Analgesic activities of these new compounds were measured by tail immersion and formalin tests for acute and chronic pains, respectively. Also, the outcomes were compared with control and PCP (10 mg/kg) groups. Results: The results indicate that compounds III, IV, and V have more acute and chronic antinociceptive effects than PCP and compound II which may be concerned with more antagonizing activities of these new painkillers for the blockage of dopamine reuptake as well as high affinity for NMDA receptors PCP binding site. Conclusion: It can be concluded that the benzylamine derivative of phencyclidine with a methyl group on the benzyl position on phenyl ring (V) is a more appropriate candidate to reduce acute and chronic (thermal and chemical) pains compared to other substituted phenyl analogs (II-IV) and PCP.

The effect of 8β-methyl group on the conformation of the ring of a 2,3-disubstituted triterpenes

1974 ◽  
Vol 39 (12) ◽  
pp. 3741-3755 ◽  
Author(s):  
J. Klinot ◽  
M. Buděšínský ◽  
S. Hilgard ◽  
A. Vystrčil
Keyword(s):  
Methyl Group

Synthesis and characteristics of ethylenediamine-N,N'-di-S-α-isovalerate and isomers of its cobalt(III) complexes

1982 ◽  
Vol 47 (1) ◽  
pp. 210-216 ◽  
Author(s):  
Milan Strašák ◽  
František Bachratý ◽  
Jaroslav Majer
Keyword(s):  
Amino Acids ◽  
Absolute Configuration ◽  
Electronic Absorption ◽  
Electronic Absorption Spectra ◽  
Chemical Parameters ◽  
Methyl Group ◽  
Nmr Data ◽  
Physico Chemical ◽  
Natural Amino Acids ◽  
C Nmr

The synthesis and physico-chemical parameters are described of a new complexone based on natural amino acids, viz. ethylenediamine-N,N'-di-S-α-isovalerate (SS-EDDIV). 1H- and 13C-NMR data revealed that the methyl group in the substance are not equivalent. The isomers of the cobalt(III) complex with the asymmetric tetradentate SS-EDDIV ligand were prepared and separated; their characteristics are given. The absolute configuration of two of the five theoretically feasible isomers was determined based on their electronic absorption spectra and circular dichroism data.

A New Dimeric Derivative of Ethoxyquin from Its Reaction with Alkylperoxy Radicals

1993 ◽  
Vol 58 (8) ◽  
pp. 1914-1918 ◽  
Author(s):  
Jaroslav Kříž ◽  
Luděk Taimr
Keyword(s):  
Mass Spectrometry ◽  
Nmr Spectroscopy ◽  
Peroxy Radicals ◽  
Methyl Group ◽  
Alkylperoxy Radicals ◽  
C Nmr

The structure of a new compound formed in the reaction of ethoxyquin with alkylperoxy radicals was resolved by 1H and 13C NMR spectroscopy (including COSY, NOESY, HHC RCT and SSLR INEPT techniques) and confirmed by mass spectrometry. The structure suggest participation of 4-methyl group of ethoxyquin in the deactivation of peroxy radicals. A mechanism of this reaction is proposed.

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