Phase Transfer Catalysis Conditions Research Articles

ChemInform Abstract: Synthesis of β-Hydroxy-α-amino Acids by Aldol Condensation Using a Chiral Phase-Transfer Catalyst.

Abstract Efficient, nearly racemic syntheses of β-hydroxy-α-amino acids by aldol condensations between t -butyl (diphenylmethy]ene)glycinate 2 and aldehydes under phase transfer catalytic conditions in the presence of the chiral catalyst N-benzylcinchoninium chloride are described.

ChemInform Abstract: Synthesis of N-(Aminoethyl)azoles Under Phase-Transfer Catalysis.

Abstract A convenient procedure is reported for the N-alkylation of azoles with 2-chloroethylamine under phase-transfer catalysis conditions.

ChemInform Abstract: New Ideas on Phase-Transfer Catalysts: SN2 Reaction with a Solid Ionophoric Salt.

A new mechanism of substitution between n-hexyl bromide (RBr) and solid potassium chloride in toluene under phasetransfer catalysis conditions is suggested, involving the formation of intermediates, adsorbed on the solid phase, viz., two binary (KCl·QX and KX·QBr) and two ternary (QX·KCl·RBr and QBr·KX·RCl) complexes. According to this mechanism, the catalytic activity of onium salts (QX) in the substitution changes in the order QI > QBr > QCl. The nature of the catalyst cation has little or no effect on the reaction rate. A general rule is proposed according to which in this reaction the substrate is attacked by a stronger nucleophile whereas a weaker nucleophile accepts the leaving group of the substrate. These and earlier data are interpreted in term of the SN2 process occurring on the solid-phase surface. The structure of the ternary complexes and the role of the phase-transfer catalyst are discussed.

ChemInform Abstract: Synthesis of 2-Amino Acids via Selective Mono-N-alkylation of Trichloroacetamide by 2-Bromo Carboxylic Esters Under Solid-Liquid Phase-Transfer Catalysis Conditions.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform Abstract: Tetramethylammonium Salts: Highly Selective Catalysts for the Preparation of gem-Dichlorocyclopropanes from Electrophilic Alkenes and Chloroform Under Phase-Transfer Catalysis Conditions.

ChemInform Abstract: Tetramethylammonium Salts: Highly Selective Catalysts for the Preparation of gem-Dichlorocyclopropanes from Electrophilic Alkenes and Chloroform Under Phase-Transfer Catalysis Conditions.

ChemInform Abstract: Derivatives of Furo(3,2-b)pyrrole.

A number of methyl 2-substituted, 2,3-disubstituted-4 H -furo[3,2- b ]pyrrole-5-carboxylates ( V - VII ) and methyl 1 H -benzo[ b ]furo[3,2- b ]pyrrole-2-carboxylate ( VIII ) was prepared by the thermolysis of corresponding methyl 2-azido-3-(R 1 ,R 2 -substituted-2-furyl)propenoates ( I - IV ). N -Methyl and N -benzyl derivatives IX - XVI were prepared at the phase-transfer catalysis conditions. Hydrolysis of some N -methyl and N -benzyl substituted esters furnished corresponding acids XVII - XXII . The hydrazides XXIII - XXX were obtained from corresponding esters and hydrazine hydrate. The preparation of 1-benzylbenzo[ b ]furo[3,2- b ]pyrrole ( XXXI ) is described as well.

ChemInform Abstract: Synthesis of 2,3-Bis(hydroxymethyl)quinoxaline 1,4-Di-N-oxide Esters under Phase-Transfer Catalysis Conditions.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Synthesis 2-ferrocenylpropan-2-ol under conditions of phase-transfer catalysis and kinetic relations holding in this reaction

2-Ferrocenylpropan-2-ol was synthesized by addition of ferrocene to acetone in the two-phase system petroleum ether-water using H2SO4-DEANaph as catalyst. Study on the kinetic parameters of the process showed that during the first two hours (conversion 87%) the reaction is of first order in ferrocene. The energy of activation of the addition of ferrocene to acetone under conditions of phase-transfer catalysis was estimated at 21 kcal mol−1.

Synthesis of terpenoid bis-α-sulfanyl oximes and macrocycles on their basis

A reaction of simple α,ω-dithiolates with (+)-3-carene and (-)-6h-pinene p-nitroso chlorides goes through the substitution for the chlorine atoms at the quaternary carbon atoms with retention of configuration leading to the corresponding bis-6h-sulfanyl oximes. Their reaction with dichloromethane under conditions of phase-transfer catalysis takes place at the oxime hydroxyl and gives sulfur-containing macrocyclic compounds.

ChemInform Abstract: Addition of Fluorene to Schiff Bases.

Addition of fluorene to N-arylmethylideneanilines under conditions of phase-transfer catalysis gives N-aryl-N-[9H-fluoren-9-yl(aryl)methyl]amines 3a–e.

ChemInform Abstract: Synthesis of Ethyl Phenoxyacetate Derivatives under Phase-Transfer Catalysis Conditions or under Ultrasound.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform Abstract: Novel Concise Synthesis of 2-Substituted 3,4-Dihydro-2H-1,4-benzoxazines by Ring Opening of Glycidols under Solid-Liquid Phase Transfer Catalysis Conditions.

The ring opening of glycidols with N-(2-fluorophenyl)toluene-p-sulfonamide under SL-PTC conditions, followed by ring closure with ButOK, provides a novel high yielding synthesis of 2-substituted 3,4-dihydro-2H-1,4-benzoxazines.

ChemInform Abstract: Selective N(1)-Arylation of Benzotriazole with Activated Aryl Halides under Conditions of Phase Transfer Catalysis.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform Abstract: Phase-Transfer Catalysis in Electrophilic Substitution Reactions. Part 8. Nitration of Arenes with Sodium Nitrite in Acid Medium under Conditions of Phase-Transfer Catalysis.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform Abstract: Synthesis of Indan-Based Unusual α-Amino Acid Derivatives under Phase-Transfer Catalysis Conditions.

Conformationally constrained cyclic α-amino acid derivatives were synthesized under solid-liquid phase-transfer catalysis conditions. This methodology involves the bis-alkylation of ethyl isocyanoacetate with various α,α‘-dibromo-o-xylene derivatives [α,α‘-dibromo-o-xylene 5, 2,3-bis(bromomethyl)-1,4-dimethoxybenzene 6, 1,2-bis(bromomethyl)-4,5-dibromobenzene 7, 2,3-bis(bromomethyl)naphthalene 8, 1,8-bis(bromomethyl)-naphthalene 9, 6,7-bis(bromomethyl)-2,2-dimethyl-1H-phenalene-1,3(2H)-dione 10, 2,3-bis(bromomethyl)-1,4-anthraquinone 11, 6,7-bis(bromomethyl)quinoxaline 12, 3,4-bis(bromomethyl)furan 13, 1,2,4,5-tetrakis(bromomethyl)benzene 28, and hexakis(bromomethyl)benzene 30] using potassium carbonate as a base and tetrabutylammonium hydrogensulfate as a phase-transfer catalyst to give corresponding isonitrile derivatives, which upon hydrolysis with HCl in ethanol gave amino esters. Using this method electron-deficient as well as electron-rich and halogen-substituted indan-based α-amino acids were prepa...

ChemInform Abstract: Phase Transfer Catalyzed Synthesis of Amides and Esters of 2,4-Dichlorophenoxyacetic Acid.

Abstract A convenient procedure is reported for the preparation of amides and esters via the reaction of 2,4-dichlorophenoxyacetyl chloride with amines or phenols under the condition of liquid-liquid phase transfer catalysis using polyethylene gtycol-600 as the catalyst. The products have been characterised on the basis of analytical and spectral (IR and H-NMR) data.

ChemInform Abstract: Phase Transfer Catalysis: Some Recent Applications in Organic Synthesis

Abstract A survey dealing with the use of anhydrous potassium carbonate as an efficient base for promoting organic reactions under solid–liquid phase transfer catalysis (SL-PTC) conditions is reported. In particular, the generation in situ of trifluoro- and trichloroacetamidide, and reactions of these azaanions with 2-bromocarboxylic esters and epoxides, affording protected α-amino acids and β-amido alcohols, respectively, are described. The reduction of allylic nitroderivatives with CS 2 to oximes or nitriles under SL- and liquid–liquid PTC (LL-PTC) is also presented. Finally, new preparation methods and a study of the reactivity of quaternary onium fluorides, hydrogendifluorides and dihydrogentrifluorides, together with the use of dihydrogentrifluorides as hydrofluorinating agents under SL-PTC conditions, are reported.

ChemInform Abstract: A Facile Synthesis of 2,6-Dibenzoyl-5-methyl-3-(substituted styryl)benzo[1,2-b; 5,4-b′]difurans (V) under Phase Transfer Catalytic Conditions and Their Antifeedant Activity.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform Abstract: Catalytic Synthesis of Allenes via Isomerization of Alkynes under Phase Transfer Catalyzed Conditions.

Catalytic isomerization of alkynes to allenes under phase-transfer catalyzed conditions is described. Commercially available quaternary ammonium salt such as tetrahexylammonium bromide acts as a very effective promoter to accelerate the reaction under mild conditions.

ChemInform Abstract: Synthesis of Sodium Diselenide under Phase Transfer Catalysis and Microwave Irradiation Conditions and Its Reaction with Benzoyl Chloride.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.