5563-78-0Relevant 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.
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.
Enantioselectivity in the Biotransformation of Mono- and Bicyclic Monoterpenoids with the Cultured Cells of Nicotiana tabacum
Hamada, Hiroki
, p. 869 - 878 (2007/10/02)
The biotransformation of the enantiomeric pairs of p-menthane and bicyclo and heptane derivatives with the cultured cells of Nicotiana tabacum was investigated.It was found that (i) the cultured cells discriminate the enantiomers of p-menthan-2-ol and bicycloheptan-2-ol and bicycloheptan-3-ol derivatives, and enantioselectively convert these alcohols to the corresponding ketones, (ii) the cells reduce the carbonyl group of p-methan-2-one derivatives to a high extent, but not that of p-menthan-3-ones, and (iii) the cells discriminate the enantiomers of bicyclohept-2-en-4-one (verbenone) and enantioselectively reduce the C-C double bond of the (1S,5S)-enantiomer.
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.
Stereoselectivity in Oxidative and Reductive Transformations of p-Menthane Derivatives with the Cultured Cells of Nicotiana tabacum
Suga, Takayuki,Hamada, Hiroki,Hirata, Toshifumi,Izumi, Shunsuke
, p. 903 - 906 (2007/10/02)
The biotransformation of the enantiomeric pairs of 2- and 3-oxygenated p-methane derivatives with the cultured cells of Nicotiana tabacum was investigated.It was found that (I) the cultured cells transform only 2-oxygenated p-menthane derivatives to a great extent, (ii) the cultured cells cause the highly stereospecific reduction for (1R,4R)-2-oxo-p-menthane, whereas this is not the case for its enantiomer, and (iii) the cultured cells enantioselectively oxidize the hydroxyl group of 2-hydroxyl-p-methanes.
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.
Reaction of (+)carvomenthol tosylate with KCN in aprotic solvents; (1S,2R,4S) 1-methyl-4-isopropylcyclohexane-2-carbonitrile
Rykowski, Zbigniew
, p. 2271 - 2278 (2007/10/02)
Reaction of (+)carvomenthol tosylate with KCN in pyridine solution was proved to produce a mixture of hydrocarbons; in DMF additionally a small quantity of alcohols was obtained.However, in DMSO sterically homogeneous (-)(1S,2R,4S) 1-methyl-4-isopropylcyclohexane-2-carbonitrile ((-)neocarvomenthyl carbonitrile) was the main product.The structure of the compound obtained was determined on the basis of spectral data, elemental analysis, and chemical transformations which indicated configurational relation of the title compound to the known (-)(1S,2R,4S) neocarvomenthyl amine.
