943-28-2Relevant academic research and scientific papers
Electrocatalytic hydrogenation of benzoic acids in a proton-exchange membrane reactor
Atobe, Mahito,Fukazawa, Atsushi,Shida, Naoki,Shimizu, Yugo
supporting information, p. 7363 - 7368 (2021/09/08)
The highly efficient chemoselective electrocatalytic hydrogenation of benzoic acids (BAs) to cyclohexanecarboxylic acids (CCAs) was carried out in a proton-exchange membrane reactor under mild conditions without hydrogenation of the carboxyl group. Among the investigated catalysts, the PtRu alloy catalyst was found to be the most suitable for achieving high current efficiencies for production of CCAs. An electrochemical spillover mechanism on the PtRu alloy catalyst was also proposed.
5-ETHYL-IMIDAZO (5,1-F) (1,2,4,) TRIAZIN-4 (3H) -ONES AS PHOSPHODIESTERASE INHIBITORS
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Page/Page column 35-36, (2010/02/07)
The invention relates to novel 5-ethyl-imidazotriazinones, processes for their preparation and their use in medicaments, esp. for the treatment and/or prophylaxis of inflammatory processes and/or immune diseases.
Separation of cis/trans-cyclohexanecarboxylates by enzymatic hydrolysis: Preference for diequatorial isomers
Koenigsberger, Kurt,Luna, Hector,Prasad, Kapa,Repic, Oljan,Blacklock, Thomas J.
, p. 9029 - 9032 (2007/10/03)
4-Substituted cis/trans-cyclohexanecarboxylates have been separated into the isomers by enzymatic hydrolysis with lipase from Candida rugosa with very good selectivity. The enzyme preferentially recognizes diequatorial conformations. Copyright (C) 1996 Elsevier Science Ltd.
Pd-Catalyzed Regio- and Stereo-selective Carboxylation of Cycloalkanes with CO
Satoh, Ko-ichi,Watanabe, Jun,Takaki, Ken,Fujiwara, Yuzo
, p. 1433 - 1436 (2007/10/02)
The reactions of cycloalkanes with CO via the C-H bond activation by Pd(OAc)2 catalyst have been found to proceed regio- and stereo-selectively to give corresponding carboxylic acids.The reactivity of C-H bonds of cycloalkanes decreases in the order: tert- > sec- > prim-carbon, and the stereochemistry of the substitutents on the main products is all equatorial.
N-(Cyclohexylcarbonyl)-D-phenylalanines and related compounds. A new class of oral hypoglycemic agents. 2
Shinkai,Nishikawa,Sato,Toi,Kumashiro,Seto,Fukama,Dan,Toyoshoma
, p. 1436 - 1441 (2007/10/02)
A series of analogues of N-(cyclohexylcarbonyl)-D-phenylalanine (5) have been synthesized and evaluated for their hypoglycemic activity. Relationships were studied between the activity and the three-dimensional structure of the acyl moiety, which was characterized by high-resolution 1H NMR spectroscopy and MNDO calculations. The role of the carboxyl group of the phenylalanine moiety was also studied by comparing the activities of the enantiomers, the decarboxyl derivative, the esters, and the amides of the phenylalanine derivatives. Thus, the structural requirements for possessing hypoglycemic activity was elucidated and a highly active compound, N-[(trans-4-isopropylcyclohexyl)carbonyl]-D-phenylalanine (13) was obtained, which showed a 20% blood glucose decrease at an oral dose of 1.6 mg/kg in fasted normal mice.
Cycloalkylmethyl Radicals. Part 3. Dynamic Stereochemistry of Axial and Equatorial Cyclohexylmethyl and 4-Alkylcyclohexylmethyl Radicals
Ingold, Keith U.,Walton, John C.
, p. 1337 - 1344 (2007/10/02)
For cyclohexylmethyl and 4-alkylcyclohexylmethyl radicals the conformer in which the CH2. group adopts the axial position and that in which the CH2. group adopts the equatorial position can both be observed by e.s.r. spectroscopy.At 140 K the axial conformers have a(Hβ) ca. 42-43 G; the equatorial conformers have a(Hβ) ca. 30-31 G.For cis-4-methylcyclohexylmethyl radicals the ratio of the concentrations of the two conformers was studied as a function of temperature and shown to depend on the rate of radical ring inversion vs. the radical lifetime; the rate constant for ring inversion was obtained.As a check on the e.s.r. results the conformational equilibrium of cis-4-methylcyclohexylmethyl bromide was studied by 1H n.m.r. spectroscopy, which gave -ΔG0300(CH2Br) = 1.91 kcal mol-1.The relative conformer concentrations were also measured as a function of temperature for cyclohexylmethyl radicals and the conformational free energy difference of the CH2. group (-ΔG0300) was found to be 0.71 kcal mol-1.The preponderance of the conformer of the cis-4-methylcyclohexylmethyl radical with the CH3 group axial at T . group cannot because of its planarity.The barriers to rotation about the Cα-Cβ bonds in the axial radicals were found to be ca. 1.0 kcal mol-1 greater than those of the equatorial radicals; this is responsible for the greater a(Hβ) values of the axial radicals.The axial and equatorial conformers of cyclohexylmethyl radicals were investigated by semi-empirical SCF MO-methods.
Hydrogenolyse en phase liquide des epoxydes du t-butyl-4 methylene-cyclohexane sur divers catalyseurs metalliques supportes
Accrombessi, Georges,Geneste, Patrick,Olive, Jean-Louis,Pavia, Andre Armand
, p. 19 - 23 (2007/10/02)
Epoxides of 4-t-butylmethylenecyclohexane have been hydrogenolised on various supported metal catalysts: Pd, Pt, Rh, Ni, at ordinary temperature and 1 atm pressure in various solvents.All these catalysts present a good regioselectivity, leading to preferential cleavage of the more substituted C-O bond.In the isomerisation process the order of reactivity is Ni Pt Pd = Rh with a yield in aldehydes of 60 percent for Pd and 80 percent for Rh and an important percentage of configuration inversion.The reaction could be used as a good method for preparing cis or trans 4-t-butylcyclohexanecarboxaldehyde.On Pt and Ni, hydrogenolysis yields primary alcohols with cleavage of the oxiran ring by trans or cis addition of hydrogen.
Stereochemistry of Alkylation of Carboxylic Acid Salt and Ester α Anions Derived from Cyclic Systems.
Krapcho, A.Paul,Dundulis, Edward A.
, p. 3236 - 3245 (2007/10/02)
A stereochemical study of the alkylation of α-lithiated carboxylate salts and esters has been performed.The α anions derived from the bicyclic acids exo-1, endo-1, and 7 (R=H) and the esters 4 and 7 (R=CH3) yield predominantly exo alkylation.As an example, the α anion derived from ester 7 (R=CH3) on treatment with CH3I yields exo-8 (R=R'=CH3) and endo-9 (R=R'=CH3) in a 97:3 ratio, a highly stereoselective reaction.Addition of TMEDA to the reactions involving the α anions derived from exo- or endo-1 did not change the stereochemical alkylation results.The α anions derived from the substituted cyclohexanecarboxylic acids 10, 13, 16, 19, or 22 (where R=H in each case) on methylation yield more axial methylation (axial/equatorial ratios of 0.4-2.7) than the α anions derived from the methyl esters corresponding to these acids.The α anions from the esters yield predominantly equatorial methylated products (e/a ratios varying from 4 to 9).The reasons for the different stereochemical results are discussed.
