Dipole moments induced in larger molecules. Triphenylmethyl derivatives

1982 ◽  
Vol 47 (6) ◽  
pp. 1733-1737 ◽  
Author(s):  
Otto Exner ◽  
Dario Iarossi ◽  
Piero Vivarelli
Keyword(s):  
Functional Groups ◽  
Quantitative Evaluation ◽  
Alkyl Group ◽  
Benzene Solution ◽  
Dipole Moments ◽  
Phenyl Group ◽  
Benzene Derivatives ◽  
Tert Butyl

Dipole moments of triphenylmethyl derivatives I-VI with electron attracting functional groups were measured in benzene solution. Comparison with respective methyl and tert-butyl derivatives revealed the moments induced in the phenyl group which are possibly somewhat greater than those induced in an alkyl group. These moments should be accounted for when determining mesomeric dipole moments of acceptor groups from benzene derivatives; however, a quantitative evaluation is not yet possible.

Dipole moments and conformation of peroxy esters

1981 ◽  
Vol 46 (2) ◽  
pp. 490-497 ◽  
Author(s):  
Božo Plesničar ◽  
Otto Exner
Keyword(s):  
Dipole Moment ◽  
Dihedral Angle ◽  
Benzene Solution ◽  
Dipole Moments ◽  
Ester Group ◽  
Model Compounds ◽  
Tert Butyl ◽  
Butyl Esters

Dipole moments of sixteen substituted peroxybenzoic esters III, IV were measured in benzene solution and interpreted in terms of the conformation around the O-O bond. The dipole moment of the CO3R group is different for R = methyl and R = tert-butyl, viz. 9.0 and 10.4 . 10-30 C m, respectively. Its solution into components was carried out making reference to the dipole moments of substituted benzoic esters as model compounds. As a result the dihedral angle τ = C-O-O-C was estimated to 160-180° in the case of tert-butyl peroxy esters IV and to 110-150° in the case of methyl peroxy esters III. The mesomeric dipole moment expressing the conjugation within the ester group was estimated to 0.8 or 1.5 . 10-30 C m for methyl or tert-butyl esters, respectively.

An Efficient Substrate-Induced Method for the Synthesis of CF3-Substituted Cyclopropanes by Metal-Free Reaction of Trifluoromethyl Styrylisoxazoles with Nitromethane

Synthesis ◽  
2020 ◽  
Author(s):  
Feng Li ◽  
Hai Ma ◽  
Qing-he Zhao ◽  
Guang-hao Yu ◽  
Ye-chen Meng ◽  
...  
Keyword(s):  
Functional Groups ◽  
Phase Transfer ◽  
Cyclization Reaction ◽  
Metal Free ◽  
Tert Butyl ◽  
Pharmacological Interest ◽  
Substituted Cyclopropanes

AbstractA series of (trifluoromethyl)cyclopropanes (TFCPs) tolerating a broad range of functional groups, known as tert-butyl bioisosteres, have been obtained from the cyclization reaction between nitromethane­ and 5-[β-(trifluoromethyl)styryl]isoxazoles in 70–94% yields and 75:25 to 90:10 dr. This method offers practical access to this cyclopropyl moiety of pharmacological interest, employing an inorganic base under phase-transfer conditions.

Dipole moments induced in larger molecule. Long-chain aliphatic esters

1982 ◽  
Vol 47 (1) ◽  
pp. 29-34 ◽  
Author(s):  
Otto Exner ◽  
Ayfer Bapçum
Keyword(s):  
Benzene Solution ◽  
Dipole Moments ◽  
Straight Chain ◽  
Basic Assumptions ◽  
Donor Acceptor ◽  
Eyring Theory ◽  
Aliphatic Esters ◽  
Long Chain

Dipole moments of straight-chain aliphatic esters Ia-Ic and IIa-IIf were measured in benzene solution. The observed trends are poorly reproduced by the classical Smith-Eyring theory; the reason may be partly the unknown conformation, partly even donor-acceptor complexes with the solvent. No deviations were observed with the highest members of the series, attributable to violation of some basic assumptions of the theory of dielectrics.

scholarly journals Cinnamic Acid Derivatives as α-Glucosidase Inhibitor Agents

2017 ◽  
Vol 17 (1) ◽  
pp. 151 ◽  
Author(s):  
Teni Ernawati ◽  
Maksum Radji ◽  
Muhammad Hanafi ◽  
Abdul Mun’im ◽  
Arry Yanuar
Keyword(s):  
Functional Groups ◽  
Cinnamic Acid ◽  
Phenyl Group ◽  
Chemical Compounds ◽  
Cinnamic Acid Derivative ◽  
Cinnamic Acid Derivatives ◽  
Glucosidase Inhibitor ◽  
Glucosidase Inhibitors ◽  
Derivatives Of ◽  
Additive Reaction

This paper reviews biological activity of some cinnamic acid derivative compounds which are isolated from natural materials and synthesized from the chemical compounds as an agent of α-glucosidase inhibitors for the antidiabetic drug. Aegeline, anhydroaegeline and aeglinoside B are natural products isolated compounds that have potential as an α-glucosidase inhibitor. Meanwhile, α-glucosidase inhibitor class of derivatives of cinnamic acid synthesized compounds are p-methoxy cinnamic acid and p-methoxyethyl cinnamate. Chemically, cinnamic acid has three main functional groups: first is the substitution of the phenyl group, second is the additive reaction into the α-β unsaturated, and third is the chemical reaction with carboxylic acid functional groups. The synthesis and modification of the structure of cinnamic acid are very influential in inhibitory activity against α-glucosidase.

13C lithiation shifts in aldimines and ketimines. Evidence on the configuration of lithiated N-tert-butylimines

1981 ◽  
Vol 59 (20) ◽  
pp. 3007-3011 ◽  
Author(s):  
Robert R. Fraser ◽  
Noemi Chuaqui-Offermanns
Keyword(s):  
Alkyl Group ◽  
Tert Butyl

The 13C shieldings for a series of aldimines and ketimines have been measured along with the shifts for their 1-lithio derivatives. For those aldimines with a primary or secondary alkyl group attached to nitrogen, the "lithiation shifts" for the attached carbon (C-4) were all upfield due to the change from anti to syn configuration on lithiation. In the ketimines and in the N-tert-butyl aldimines and ketimines, the lithiation shifts for the C-4 carbon failed to provide stereochemical information. The shifts at C-1 and C-2 proved similar to those previously observed for lithiated alkenes.

scholarly journals Determination of the dipole moments of some polar liquids dissolved in polar solvents

1969 ◽  
Vol 47 (20) ◽  
pp. 3767-3771 ◽  
Author(s):  
H. A. Rizk ◽  
N. Youssef ◽  
H. Grace
Keyword(s):  
Dipole Moments ◽  
Butyl Alcohol ◽  
Polar Solvents ◽  
Tert Butyl ◽  
Tert Butyl Alcohol ◽  
Initial Decrease ◽  
Interacting Systems ◽  
Solvent Molecules ◽  
Onsager Equation

The application of a modified form of the Onsager equation at the condition of infinite dilution of a polar solute in a polar solvent leads to reasonable dipole moments for water, pyridine, acetone, tert-butyl alcohol, n-butyl alcohol, and β-octyl alcohol, except in the case of water in tert-butyl alcohol at 30 and 40 °C and the case of acetone in n-butyl alcohol at 30 to 50 °C. The initial decrease of the dielectric constant of solvent by addition of solute in each of these two cases is associated with a reduction in the Kirkwood g-factor of solute. In all 12 systems investigated, strong hydrogen bonding occurs between solute and solvent molecules and often between solvent molecules themselves. It is thought that this equation must fail when short-range interactions assume predominant importance, but why it works so well for those cases which are also strongly interacting systems is not clear.

Thermodynamics of metal-ligand bond formation. II. Zinc, cadmium, and mercury(II) complexes of o,o-dialkyldithiophosphates

1971 ◽  
Vol 24 (10) ◽  
pp. 2077 ◽  
Author(s):  
DR Dakternieks ◽  
DP Graddon
Keyword(s):  
Metal Atom ◽  
Alkyl Group ◽  
Thermodynamic Data ◽  
Benzene Solution ◽  
Bond Formation ◽  
Free Energies ◽  
Zinc Cadmium ◽  
Metal Ligand ◽  
Ligand Bond

The reactions of 0,O-dialkyldithiophosphato complexes, {(R0)2PSz}zM (M = Zn, Cd, Hg), to form dimers and 1 : 1 and 1 : 2 adducts with pyridine have been studied calorimetrically in benzene solution a t 30�C. While variation of the alkyl group has little effect, variation of the metal atom causes marked changes in both free energies and enthalpies of reaction. Average values of thermodynamic data obtained are as follows (AGOao3 and AH0300 in k J mol-l, AS0a03 in J K-l mol-l) :

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