1126-41-6Relevant academic research and scientific papers
Simple H2-free hydrogenation of unsaturated monoterpenoids catalyzed by Raney nickel
Philippov, Alexey A.,Chibiryaev, Andrey M.,Martyanov, Oleg N.
, p. 380 - 381 (2019/08/20)
A series of monoterpenoids (citral, carvone, menthone, camphor) as well as cyclohexanone and hex-5-en-2-one were subjected to transfer hydrogenation with PriOH/Raney nickel system at 82 or 150 °C. Among monoterpenoids, citral and carvone underwent full conversion at 82 °C within 5 h.
P450-catalyzed regio- and stereoselective oxidative hydroxylation of disubstituted cyclohexanes: Creation of three centers of chirality in a single CH-activation event This paper is dedicated to the memory of Harry H. Wasserman
Ilie, Adriana,Agudo, Rubén,Roiban, Gheorghe-Doru,Reetz, Manfred T.
, p. 470 - 475 (2015/02/02)
Wild-type P450-BM3 is able to catalyze in a highly regio- and diastereoselective manner the oxidative hydroxylation of non-activated disubstituted cyclohexane derivatives lacking any functional groups, including cis- and trans-1,2-dimethylcyclohexane, cis- and trans-1,4-dimethylcyclohexane, and trans-1,4-methylisopropylcyclohexane. In all cases except chiral trans-1,2-dimethylcyclohexane as substrate, the single hydroxylation event at a methylene group induces desymmetrization with simultaneous creation of three centers of chirality. Certain mutants increase selectivity, setting the stage for future directed evolution work.
Radical chain reduction of alkylboron compounds with catechols
Villa, Giorgio,Povie, Guillaume,Renaud, Philippe
supporting information; experimental part, p. 5913 - 5920 (2011/06/16)
The conversion of alkylboranes to the corresponding alkanes is classically per-formed via protonolysis of alkylboranes. This simple reaction requires the use of severe reaction conditions, that is, treatment with a carboxylic acid at high temperature (>150 °C). We report here a mild radical procedure for the transformation of organoboranes to alkanes. 4-tert-Butylcatechol, a well-established radical inhibitor and antioxidant, is acting as a source of hydrogen atoms. An efficient chain reaction is observed due to the exceptional reactivity of phenoxyl radicals toward alkylboranes. The reaction has been applied to a wide range of organoboron derivatives such as B- alkylcatecholboranes, trialkylboranes, pinacolboronates, and alkylboronic acids. Furthermore, the so far elusive rate constants for the hydrogen transfer between secondary alkyl radical and catechol derivatives have been experimentally determined. Interestingly, they are less than 1 order of magnitude slower than that of tin hydride at 80 °C, making catechols particularly attractive for a wide range of transformations involving C-C bond formation.
Synthesis and reactions of enantiomerically pure dialkyl diselenides from the p-menthane group
Rafinski, Zbigniew,Scianowski, Jacek
, p. 1237 - 1244 (2008/09/21)
A convenient route for the synthesis of optically active dialkyl diselenides from the p-menthane system utilizing a reaction of alkyl tosylates and chlorides with sodium diselenide is reported. The diselenides obtained have been used for asymmetric methoxyselenenylation of styrene. Quantum chemical calculations of the chair conformers stability of the terpeneselenenyl bromides from the p-menthane group have also been carried out using density functional theory (DFT, at the B3LYP/6-311G(d) level). The influence of the diselenides structure on the stereoselectivity in the methoxyselenenylation reaction is also discussed.
Antimicrobial therapeutic compositions for oral and topical use
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Page 7; 18, (2008/06/13)
The invention provides therapeutic antimicrobial compositions comprising natural phenolic compounds and essential oil alcohols and methods of use. The therapeutic antimicrobial compositions are useful to treat internal and external bacterial, fungal, and protozoan infections, as well as antibiotic resistant and secondary opportunistic infections.
Reduction of Organic Compounds with Rare-Earth Intermetallics Containing Absorbed Hydrogen
Imamoto, Tsuneo,Mita, Takeshi,Yokoyama, Masataka
, p. 5695 - 5699 (2007/10/02)
The hydrogenation of organic compounds with rare-earth intermetallic hydrides has been investigated.Alkynes,alkenes,aldehydes,ketones,nitriles,imines, and nitro compounds are hydrogenated in excellent yields with LaNi5H6 or LaNi4.5Al0.5H5 at 0-60 deg C.The present hydrogenation method has the following characteristic features. (1) The intermetallic compounds (alloys) are not poisoned by compounds containing an amino group or a halogen atom. (2) The alloys can be used repeatedly without decrease in activity. (3) The reaction conditions are mild, and selective hydrogenations of some organic functional groups can be achieved.The reaction mechanism of this hydrogenation is briefly discussed in terms of stereochemistry and H/D exchange reactions.
Oxidoreduction between Cycloalkanols and Cycloalkanones in the Cultured Cells of Nicotiana tabacum. Simulation of the Time-courses in the Oxidation of (+)-Borneol and the Reduction of (-)-Carvomenthone
Suga, Takayuki,Izumi, Shunsuke,Hirata, Toshifumi,Hamada, Hiroki
, p. 425 - 428 (2007/10/02)
The time-courses in the oxidation of (+)-borneol and the reduction of (-)-carvomenthone in the cultured cells of Nicotiana tabacum were simulated on the basis of the permeability of 5- to 7-membered cycloalkanols and their corresponding cycloalkanones into the cultured cells and the 13C NMR chemical shifts of the carbonyl carbon of (+)-camphor which is the oxidation product of (+)-borneol and (-)-carvomenthone which is a substrate for the reduction, respectively.
Carvone- and Piperitone-Derived Allylic Stannanes and Aspects of Their Electrophilic Substitution
Young, David,Jones, Martin,Kitching, William
, p. 563 - 573 (2007/10/02)
cis- and trans-Carvotanacetols and -piperitols have been converted into the corresponding allylic chlorides, which were made to react with both trimethyltinlithium and triphenyltinlithium.The resulting allylic stannanes were characterized by 1H, 13C and 119Sn n.m.r. spectroscopy, which permitted assignment of the relative configurations.Triphenyltinlithium appears to react in a (substantially) concerted fashion with the (optically active) chloride from the carvotanacetols yielding an optically active stannane.The corresponding trimethylstannane is optically inactive.Substitution reactions (SE') with acid and sulfur dioxide (in chloroform) are preferentially γ-anti and specifically γ-syn respectively, in line with conclusions based on other cyclohex-2-enyl systems.
HYDROGENOLYSE EN PHASE LIQUIDE SUR Pd/C DES EPOXYDES DU CARVOMENTHENE ET DU LIMONENE
Accrombessi, G.,Geneste, P.,Olive, J.-L.,Pavia, A. A.
, p. 3135 - 3140 (2007/10/02)
Hydrogenolysis over Pd/C of cis and trans epoxides of carvomenthene and limonene give a mixture of hydrocarbons, secondary and tertiary alcohols, and ketones in proportions dependent upon the nature of the starting material.In the limonene epoxides, the extracyclic double bond plays an important role in the opening of the oxirane ring through a common unsaturated tertiary alcohol intermediate by double bond migration, hydrogenation of which leads to the products.For the carvomenthene epoxides the results are similar to those found in the 4-t-butyl series with competition between cis addition and trans addition of hydrogen.The presence of the isopropenyl group leads to slower reaction rates in comparison with t-butyl analogues.
Hydrogenation en phase liquide sur Pd/C de derives mono et disubstitues du limonene
Pavia, Andre Armand,Geneste, Patrick,Olive, Jean-Louis
, p. 24 - 27 (2007/10/02)
Various derivatives of limonene, either monosubstituted: cis and trans-β-terpineols, (+) neodihydrocarveol, (-) isopulegol, or disubstituted: (+)-trans-N,N-2-dimethylamino-8-trans-p-menthene-1-ol, (+)-N,N-1-dimethylaminoneodihydrocarveol and (+)-trans-N,N-2-dimethylamino-8-cis-p-menthene-1-ol, have been hydrogenated on Pd/C or Adams PtO2 at 25 deg C and under a pressure of 1 atm in ether.With PtO2 the only product obtained has the same configuration as the starting material.On the opposite, due to its isomerising character, Pd/C leads to a mixture of two stereoisomers by racemisation of the asymmetric carbon at position 4 through migration of the exocyclic isopropenyl double bond.In the case of (+) neohydrocarvomenthone (4R) the double bond enters the ring, and so (+) carvomenthone (4R) and (-) isocarvomenthone (4S) are obtained.
