cas 6230-93-9, O-METHYL-L-TYROSINE | Articles data

Articles about 6230-93-9Total 8 be found

Stereochemical inversion of phosphonothioate methanolysis by La(III) and Zn(II): Mechanistic implications for the degradation of organophosphate neurotoxins
The utility of phosphonothioate methanolysis to degrade organophosphate neurotoxins has prompted the stereochemical investigation of this useful transformation. The methanolysis of enantiomerically pure O,S-diethyl phenylphosphonothioate (5) was studied b
Kuo, Louis Y.,Glazier, Sara K.
experimental part
p. 328 - 335
(2012/03/12)

Enantiopure O-substituted phenylphosphonothioic acids: Chiral recognition ability during salt crystallization and chiral recognition mechanism
The chiral recognition ability of enantiopure O-methyl, O-ethyl, O-propyl, and O-phenyl phenylphosphonothioic acids (1a-d) for various kinds of racemic amines during salt crystallization and the chiral recognition mechanism were thoroughly investigated. T
Kobayashi, Yuka,Morisawa, Fumi,Saigo, Kazuhiko
p. 606 - 615
(2007/10/03)

Optical resolution reagent and manufacturing method of optically active amines that uses it
PROBLEM TO BE SOLVEDTo provide an effective reagent for optical resolution which produce an optically active amines by resolving the (+/-)-amines and the method for producing the optically active amines characterized by using the same reagent. SOLUTION The O-alkylthiophosphoric acid represented as the following formula (1) is effective for the optical resolution of various amines.
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Page/Page column 18

(2008/06/13)

A new hydrogen-bonding motif for chiral recognition in the diastereomeric salts of racemic 1-phenylethylamine derivatives with enantiopure O-ethyl phenylphosphonothioic acid
(Chemical Equation Presented) An enantiopure phosphonothioic acid showed a unique and superior chiral recognition ability, arising from its P-stereogenicity, for racemic 1-phenylethylamine derivatives through diastereomeric crystallization. Spherical molecular clusters, associated by hydrogen bonds and CH/π interactions, aggregated with high symmetry in the less-soluble diastereomeric salts.
Kobayashi, Yuka,Morisawa, Fumi,Saigo, Kazuhiko
p. 4227 - 4230
(2007/10/03)

Micellar catalysis of hydroperoxide anion assisted hydrolysis of O-p-cyanophenyl O-ethyl phenylphosphonothionate
The micellar catalyzed reaction between hydroxide or hydroperoxide anion and O-p-cyanophenyl O-ethyl phenylphosponothionate has been examined.Addition of carbonate and borate ions in buffered medium (pH 10) and chloride ion in unbuffered medium has revealed salt effects of three different kinds: (i) increased micellar binding (salting out), (ii) formation of peroxyborate ion, and (iii) counterion effect respectively.The kinetic rate data in hydroxide reaction have been accounted quantitatively in terms of pseudophase ion-exchange model, but this model could be utilized only quantitatively for analysis of reaction with HO2-.
Danikhel. R. K.,Purnanand
p. 856 - 860
(2007/10/02)

SILICON-PHOSPHORUS ANALOGIES. NUCLEOPHILIC CATALYSIS IN THE ALCOHOLYSIS OF CHLOROPHOSPHORUS DERIVATIVES
The mechanism of the alcoholysis of chlorophosphonates and chlorophosphates in presence of nucleophilic catalysts like hexamethylphosphotriamide, pyridine and N-methylimidazole is discussed on the basis of kinetic and stereochemical results.We have proposed a mechanism for the reaction, which is governed by entropy, involving reaction of the alcohol with a pentacoordinated intermediate.This accounts for the differences in the stereochemical outcome and the rate equation which can be derived for the reaction with a variety of substrates in addition to the absence of common ion + solvent effects observed.
Corriu, Robert J. P.,Lanneau, Gerard F.,Leclercq, Dominique
p. 1959 - 1974
(2007/10/02)

SILICON-PHOSPHORUS ANALOGIES. PARTICIPATION OF EXTERNAL NUCLEOPHILES TO ACTIVATED PROCESSES OF RACEMIZATION AND HYDROLYSIS OF CHLOROPHOSPHONO DERIVATIVES
Kinetic and stereochemical studies show nucleophilic assistance by dimethylformamide (DMF), dimethylacetamide (DMA), hexamethylphosphotriamide (HMPT) and N-methylimidazole (NMI) in racemization and solvolysis of menthylchloro(phenyl)phosphonate, 1a, and O-ethylchloro(phenyl)thiophosphonate, 2.Similar orders of nucleophilic reactivity (Nu = NMI >> HMPT > DMF> DMA), and identical rate laws (vrac = k 2 and vH2O = k') are consistent with a common mechanism, governed by entropy (-60 u.e/= -40 u.e.).Analogies between reaction mechanisms at silicon and phosphorus are clearly evidenced.A two step process, involving rate-determining attack on a pentacoordinate complex is discussed.
Corriu, R. J. P.,Lanneau, G. F.,Leclercq, D.
p. 1617 - 1626
(2007/10/02)

Photoreduction and Photoarylation of O-Ethyl S-n-Propyl Phenylphosphonothioate
U.v. irradiation (254 nm) of O-ethyl S-n-propyl phenylphosphonothioate (1) in EtOH leads to a rapid photoreductive cleavage of the phosphorus-sulphur (Φ = 0.14) or the sulphur-carbon (Φ = 0.05) bond, as evidenced by the formation of O-ethyl phenylphosphinate, n-propanethiol, O-ethyl phenylphosphonothioic acid, and propane as the major products.The concomitant photo-oxidation of EtOH to acetaldehyde is also observed.The rate of photoreduction of (1) is independent of the hydrogen-donor capacity of the solvent (MeOH, EtOH, or PriOH).Hence the reaction proceeds without prior hydrogen abstraction, probably by direct homolysis of the excited state of (1).In accordance with this, in situ spin-trapping experiments show the intermediacy of the phosphonyl radical EtO(Ph)P(O).Sensitizers with a triplet energy 80 kcal mol-1 sensitize the photoreduction of (1).Sensitization by aromatic hydrocarbons, e. g. benzene, in found to be complicated by simulataneous photoarylation of (1), which leads to the formation of O-ethyl diphenylphosphinate.
Benschop, Hendrik P.,Konings, Cornelis A. G.,Platenburg, Dominique H. J. M.,Deen, Rudolf
p. 198 - 205
(2007/10/02)