NMR study of reactions of organyltrichlorophosphonium hexachlorophosphorates with triethylamine

Abstract

The reactions of trichloro(2 ethoxyethenyl)phosphonium and trichloro(styryl)phosphonium hexachlorophosphorates with triethylamine were studied by 1 Н, 13 С, and 31 Р NMR spectro scopy. It was shown that phosphonyl chlorides are the primary products of the reactions. The presence of the alkoxy group in hexachlorophosphorate results in the oxidation of the PCl 2 group to form phosphonyl chlorides. Diphosphorylated oxaphosphinines were synthesized.Chemistry of unsaturated organophosphorus com pounds is among vigorously developed sections of organo phosphorus chemistry. Interest in unsaturated organo phosphorus compounds is caused by their significance for synthetic chemistry of macromolecular materials, complexones, extragents, antipyrenes, drugs, and phos phorus containing pesticides. 1-3 Earlier we studied the phosphorylation of unsaturated compounds, N vinylazoles and their derivatives, and other organic nucleophiles by phosphorus pentachloride derivatives. 4-17 In particular, it was shown that many N vinylazoles react with phos phorus pentachloride to form unsaturated organophos phorus compounds containing tetra , penta , and hexa coordinated phosphorus atoms. 4,9-12,16,17 The phos phorylation of tertiary amines containing at least two ethyl groups at the nitrogen atom by phosphorus pentachloride affords new C chlorophosphorylated enamines. 5 At the same time, the presence in the amine molecule of two aryl substituents and one ethyl group deactivates the latter, and no phosphorylation occurs. The possibility of substi tution of two chlorine atoms in the PCl 5 molecule by alk enyl groups was demonstrated for N ethyl N methyl aniline. 5 There are no indications in literature to the possibility of using accessible alkenyltrichlorophosphonium hexa chlorophosphorates for the phosphorylation of ethers, di alkenyl sulfides, and tertiary amines. The most abundant * Dedicated to Academician of the Russian Academy of Sciences V. I. Minkin on the occasion of his 80th birthday.

C- and N-Phosphorylated Enamines—An Avenue to Heterocycles: NMR Spectroscopy

“…The phosphorylation of tertiary N-ethylamines with phosphorus pentachloride has been studied in detail by two-dimensional (2D) and multinuclear 1 H, 13 C and 31 P NMR spectroscopy [14,24,25]. The tertiary amines, containing at least two ethyl groups (triethylamine, diethylaniline, diethylbenzylamine), react with phosphorus pentachloride under mild conditions (15-20 • C) to form hexachlorophosphorates of 2-aminoethenyltrichlorophosphonium (1-3) and hexachlorophosphorates of 2-amino-1-chloroethenyltrichlorophosphorates (4)(5)(6).…”

“…The 1 H, 13 Table 1. The 1 H, 13 C and 31 P NMR chemical shifts (δ, ppm) and coupling constants (J, Hz) of phosphorylated enamines 1-13.…”

“…Table 1. The 1 H, 13 C and 31 P NMR chemical shifts (δ, ppm) and coupling constants (J, Hz) of phosphorylated enamines 1-13. This was confirmed by studies of the reaction mixture by 31 Р NMR spectroscopy [24].…”

“…Organic derivatives of phosphorus pentachloride in various coordination states, including the products of phosphorylation of alkenes and heterocycles based on them, can be conveniently studied by 31 P NMR spectroscopy. As is known, phosphorus pentachloride, a 2 of 40 common electrophilic phosphorylating agent, dissociates into ions both in the crystalline state and in polar solvents and exists in a pentacoordinated state in nonpolar solvents: 2 PCl 5…”

“…PCl + 4 + PCl − 6 A variation in the coordination number of phosphorus from 3 to 6 significantly changes the shielding of the 31 P nucleus from about +200 to −300 ppm: The tetra-, penta-and hexacoordinated states of phosphorus pentachloride can be very easily characterized by multinuclear multipulse NMR spectroscopy and, in particular, by 31 P NMR spectroscopy [9].…”