Reactions of trialkylphosphine radical cations with cycloalkenes

Electrochemical oxidation of tertiary aliphatic phosphines in the presence of cyclohexene or cyclopentene yields isomeric cycloalkenylphosphonium salts with different positions of the double bond in the cycloalkenyl substituent relative to the phosphonium group

Electrochemical Oxidation of Metal Dialkyl Phosphites and Their Reaction with Halogens

Electrochemical oxidation of sodium dialkyl phosphites with alkyl radicals of normal structure leads to formation of tetraalkyl pyrophosphites as the main products, while electrochemical oxidation of litium dialkyl phosphites and sodium salts with branched alkyl radicals yields tetraalkyl hypophosphates. The reaction of metal dialkyl phosphites with halogens leads to analogous results

Electrochemical and Catalytic Initiation of Triethyl Phosphite Addition to Cyclohexanone

Electrochemical oxidation of triethyl phosphite in the presence of cyclohexanone results in a mixture of three products: diethyl(1-ethoxycyclohexyl)phosphonate, diethyl phosphonate, and 2-(1-cyclohexenyl)cylcyclohexanone. These products are formed through the stage on the anode synthesis of quasiphosphonium salts, which initiate addition of triethyl phosphite to cyclohexanone and condensation of cyclohexanone. The fact that quasiphosphonium salts catalyze addition of the phosphite to the ketone was proved by independent experiment

Radical Cations of Phosphorous Amides in Reactions with Alkenes

Electrochemical oxidation of diethyl diethylphosphoramidite and ethyl tetraethylphosphorodiamidite in the presence of alkenes results in formation of amido(1-alkenyl)- and amido(2-alkenyl)phosphonates. Under the same conditions, hexaethylphosphorous triamide forms a dodecaethylhexaaminodiphosphonium salt. Electrochemical oxidation of the above phosphoramidites and -diamidites in the presence of diethyl hydrogen phosphite or O,O-dibutyl hydrogen thiophosphite and an alkene involves addition of (RO)2P(O,S)H at the multiple bond and yields a different ratio of isomeric mono- and diamidoalkenylphosphonates

Quantum-chemical estimation of the stability and reactivity of diphosphonium salts

For a series of diphosphonium salts containing two positively charged covalently bonded phosphorus atoms, XnY3-nP +P+XnY3-n (X = alkyl substituent, Y = amino group, n = 0-3), the stability, reactivity, and P-P bond strength were evaluated by various physicochemical methods. The P-P bond energy is appreciably influenced by both steric factors and donor properties of the substituents. The calculations confirmed that transformations of diphosphonium salts can involve cleavage of both P-P and P-N (or P-C) bonds

Mechanism of Electrochemical Synthesis of Phosphonium and Quasiphosphonium Salts

The radical cations generated on the anode in the course of electrochemical oxidation of tripropylphosphine in the presence of toluene and water are established to react with the aromatic compound and initial phosphine rather than with water molecules. The experimental findings made it possible to propose a new method of electrochemical synthesis of arylphosphonium salts. The electrochemical synthesis of quasiphosphonium salts, performed by electrochemical oxidation of tertiary phosphines in the presence of alcohols, amines, phenols, thiols, and disulfides, is assumed to involve a diphosphonium intermediate, while the synthesis of arylphosphonium cations proceeds by the mechanism of free-radical aromatic substitution

Free-Radical Phosphorylation of Olefins Initiated by Anodic Oxidation

Electrochemical oxidation of lithium and sodium dialkyl phosphites generates dialkyl phosphonyl radicals, which initiate chain free-radical addition of dialkyl phosphites across the alkene multiple bond to form alkyl(cycloalkyl)phosphonates. Alkyl(cycloalkyl)phosphonates are formed simultaneously owing to anodic oxidation of adsorbed primary radical adducts of phosphonyl radical and alkene molecule to give the carbenium cation, followed by deprotonation of the latter

Quantum-chemical estimation of the stability and reactivity of diphosphonium salts

For a series of diphosphonium salts containing two positively charged covalently bonded phosphorus atoms, XnY3-nP +P+XnY3-n (X = alkyl substituent, Y = amino group, n = 0-3), the stability, reactivity, and P-P bond strength were evaluated by various physicochemical methods. The P-P bond energy is appreciably influenced by both steric factors and donor properties of the substituents. The calculations confirmed that transformations of diphosphonium salts can involve cleavage of both P-P and P-N (or P-C) bonds

Electrochemically induced phosphorylation of alkenes

The processes of electrochemical phosphorylation of alkenes were investigated. It was found that anodically generated radical-cations of trialkyl phosphites, dialkyl trimethylsilyl phosphites, mono-and diamidophosphites were added to olefin molecules to give unsaturated alkenephosphonates. The anodic oxidation of tetraalkyl pyrophosphites proceeds with disintegration of initial radical-cations and leads to mixture alkane-and alkenephosphonates. Greater amounts of alkanephosphonates were formed during anodic oxidation of sodium (or lithium) dialkyl phosphites in the presence of alkenes. © 1997 Published by Elsevier Science Ltd

Radical Cations of Phosphorous Amides in Reactions with Alkenes

Electrochemical oxidation of diethyl diethylphosphoramidite and ethyl tetraethylphosphorodiamidite in the presence of alkenes results in formation of amido(1-alkenyl)- and amido(2-alkenyl)phosphonates. Under the same conditions, hexaethylphosphorous triamide forms a dodecaethylhexaaminodiphosphonium salt. Electrochemical oxidation of the above phosphoramidites and -diamidites in the presence of diethyl hydrogen phosphite or O,O-dibutyl hydrogen thiophosphite and an alkene involves addition of (RO)2P(O,S)H at the multiple bond and yields a different ratio of isomeric mono- and diamidoalkenylphosphonates