1,2:5,6-Di-O-Cyclohexylidene- d -Mannitol and Its Bis(Trimethylsilyl) Ether in the Dithiophosphorylation Reactions

© 2016 Wiley Periodicals, Inc.The reaction of 2,4-diaryl 1,3,2,4-dithiadiphosphetane-2,4-disulfide with diketonide of d-mannitol has been found to give optically active bisaryldithiophosphonic acids transformed into the corresponding diammonium salts by the treatment of n-hexadecylamine. O,O-Bis(trimethylsilyl) ether of d-mannitol ketonide reacts with 2,4-diaryl 1,3,2,4-dithiadiphosphetane-2,4-disulfide to form chiral S,S-disilylbisaryldithiophosphonate. Diammonium bisaryldithiophosphonate possesses antibacterial activity against Staphylococcus aureus ATCC 6538-P

Kinetic study of the reaction of tertiary phosphines with acrylic acid in aprotic solvents

The kinetics of the reaction of tertiary phosphines with acrylic acid in a series of aprotic solvents was studied by spectrophotometry. The data obtained suggest a stepwise mechanism of interaction including initial formation of zwitterionic intermediate followed by intermolecular proton transfer to the generated carbanionic center from the second molecule of acrylic acid. Copyright © Taylor & Francis Group, LLC

Terpene analogues of dithiophospate pesticides

New optically active O,O-diterpenyl dithiophosphoric and O-terpenyl aryldithiophosphonic acids were prepared when chiral terpenols such as (1R)-endo-(+)-fenchyl alcohol, (1S)-endo-(-)-borneol, (1R)-(-)-nopol, and (1R,2S,3S,5R)-(+)-isopinocampheol were involved in reactions with tetraphosphorus decasulfide and 2,4-diaryl 1,3,2,4- dithiadiphosphetane-2,4- disulfides. Copyright © Taylor & Francis Group, LLC

Kinetics and mechanism of triphenylphosphine quarternization with unsaturated carboxylic acids in various media

Reactions of tertiary phosphines with unsaturated electrophilic reagents are widely used in synthetic organic chemistry. Typical satellites of these transformations are proton migration processes, which can play decisive role in such reactions. To learn more about proton transfer mechanism, kinetics of reaction of triphenylphosphine with a series of unsaturated carboxylic acids in alcohols, carboxylic acids, and aprotic solvents was studied by spectrophotometry. The form of kinetic equation depends on proton-donor properties of solvent and has a general third order. Proton transfer occurs from the solvent in carboxylic acids; the second molecule of substrate is required in aprotic solvents, and both canals of proton migration take place in alcohols. Existent proton transfer canals are isokinetic, attesting to the invariability of general features of the reaction mechanism independent of proton-donor nature at the last step of the interaction. A stepwise mechanism including initial generation of 1,3-dipole followed by proton transfer to the carbanionic centre from the medium is suggested. Copyright © Taylor & Francis Group, LLC

α-d-Glucofuranose and α-d-allofuranose diacetonides and silyl ether of α-d-glucofuranose diacetonide in dithiophosphorylation reactions

© 2016 Wiley Periodicals, Inc.α-d-Glucofuranose and α-d-allofuranose diacetonides react with 2,4-diorganyl 1,3,2,4-dithiadiphosphetane-2,4-disulfides to form optically active dithiophosphonates in 78–81% yields, which are transformed into the corresponding ammonium salts in 90–97% yields by the treatment of n-hexadecylamine. The S-silyldithiophosphonate was prepared in 93% yield by the reaction of 2,4-bis(butoxyphenyl) 1,3,2,4-dithiadiphosphetane-2,4-disulfide with silyl ether of α-d-glucofuranose diacetonide. One of the salts obtained possesses antibacterial activity against Staphylococcus aureus ATCC 6538-P

Investigation of conformational equilibrium in a series of some 1,3-dioxa-2-phosphorinanes

1. The IR spectra of certain 1,3-dioxa-2-phosphorinanes were studied under conditions of various polarities of the medium and temperatures, and it was shown that 2,4-dimethy1-2-thiono- and 2-chloro-2-thiono-1,3-dioxa-2-phosphorinanes are characterized by stabilization of one conformational form, while for 2-methyl-2-thiono-1,3-dioxa-2-phosphorinane a dynamic equilibrium of two conformers is realized with an appreciable dependence of their amounts on the dielectric permeability of the medium. 2. An equilibrium of three conformers was detected for 2-chloro-4-methyl-2-thiono-1,3-dioxa-2-phosphorinane. It was hypothesized that, together with the "chair" conformation of the ring with axial and equatorial positions of the P=Sbond, the conformer with an equatorial arrangement of the P=S bond and a "boat" form of the ring participates in the equilibrium. © 1973 Consultants Bureau

Reaction of 3,4-dichloro-5-methoxyfuran-2(5H)-one with 1,2-organylbis(diphenylphosphines)

The reactions of 3,4-dichloro-5-methoxyfuran-2(5H)-one with 1,2-ethylenebis(diphenylphosphine) and 4,5-bis(diphenylphosphinyl)-2-phenylpyridazin-3(2H)-one involve substitution of both chlorine atoms with σ3-P atoms to form unstable diphosphonium bicyclic salts which in the course of the reaction undergo an unusual fragmentation to give finally mono-and tricyclic diphosphoniacyclohexane structures

The cycloaddition of N,N-dimethylaminomethylidene-P-phenylphosphine to vinylallenylphosphonates

The cycloaddition of N,N-dimethylaminomethylidene-P-phenylphosphine (I) to α-vinylallenylphosphonates (II) proceeds regioselectively with the formation of 2-dimethylamino-5-dialkoxyphosphoryl-6-isopropylidene-1-phenyl-1,2,3-tetrahydro-λ3-phosphorine (III). © 1990 Plenum Publishing Corporation

Synthesis and properties of phosphabetaine structures: III. Phosphabetaines derived from tertiary phosphines and α,β-unsaturated carboxylic acids. Synthesis, structure, and chemical properties

Methods of synthesis of acylate phosphabetaines by reactions of triphenylphosphine with methacrylic, cinnamic, and p-methoxycinnamic acids are developed. The phosphabetaine form is proposed to exist in equilibrium with the (σ5-oxaphospholane form. The features of methylation of the phosphabetaines are discussed

Synthesis and properties of phosphabetaine structures: IV. 3-(triphenylphosphonio)propanoate in reactions with dipolar electrophilic reagents

Reactions of 3-(triphenylphosphonio)propanoate with heterocumulenes, such as phenyl isocyanate and dicyclohexylcarbodiimide, we studied under the assumption that they proceed by nucleophilic addition and 1,4-dipolar cycloaddition schemes. Quantum-chemical calculations show that the σ5-phosphorane cycloadduct of the betaine with isocyanate is thermodynamically preferred over its isomeric zwitter-ionic adduct. However, the experimental evidence suggests that the reaction with phenyl isocyanate involves nucleophilic addition of the betaine to isocyanate followed by hydrolysis to firm finally a complex of the starting betaine with diphenylurea. The structure of the complex was established by X-ray diffraction analysis. The revealed above controversy is explained by a high protophilicity of betaine structures, which is also confirmed by the results of the reaction of the betaine with carbodiimide. © Pleiades Publishing, Inc., 2006