https://onlinelibrary.wiley.com/doi/pdf/10.1002/hc.21394

A study on the acidic hydrolysis of cyclic phosphinates: 1-Alkoxy-3-phospholene 1-oxides, 1-ethoxy-3-methylphospholane 1-oxide, and 1-ethoxy-3-methyl-1,2,3,4,5,6-hexahydrophosphinine 1-oxide

A completely water soluble azobenzene chemosensor 1 for selective detection of Hg2+ was synthesized. Taking advantage of the absorption changes corresponding to the transition moments polarized along the short axis of an azobenzene, 1 showed characteristic UV-Vis signal changes in the band around 240 nm for Hg2+ in wide pH ranges, which also showed good tolerance to various metal ions and photoirradiation. Upon addition of Hg2+ into the solution of 1, a favored formation of trans-1 was observed, which is attributed to an intramolecular coordination of the PEG chain and Nβ to Hg2+ confirmed by a control experiment test.

Selective mercury(ii) detection in aqueous solutions upon the absorption changes corresponding to the transition moments polarized along the short axis of an azobenzene chemosensor

Two step acidic hydrolysis of dialkyl arylphosphonates

This chapter summarizes the results of the Keglevich group obtained in the title subject in the last decade. In the first part, the direct esterification and other derivatizations of five- and six-ring phosphinic acids accomplished under microwave (MW) conditions are discussed. It is noteworthy that these kinds of derivatizations do not take place on conventional heating. Energetics of the above reactions evaluated by quantum chemical calculations justified the experimental results. The cyclic phosphinates were also prepared by the MW-assisted alkylating esterification of the corresponding phosphinic acids in solid–liquid phase. Applying alkyl halides of normal reactivity, the application of a phase-transfer catalyst was beneficial. Then, reactions are discussed, where the MW irradiation has a significant accelerating effect. Such reactions are the Diels–Alder reactions resulting in bridged P-heterocycles, their fragmentation-related phosphorylations and the so-called inverse Wittig-type reactions furnishing β-oxophosphoranes. The next part includes phospha-Michael additions resulting in the formation of precursors of bidentate P-ligands. Finally, the MW-assisted Kabachnik–Fields condensations affording N - and P -heterocyclic derivatives of α-aminophosphonates and α-aminophosphine oxides are summarized. It was also possible to realize bis(phospha-Mannich) reactions. A part of the bis(products) were useful in the synthesis of the corresponding ring platinum complexes. Most of the above reactions were carried out without the use of any solvent and the advantage of the MW variations was proved by comparative thermal experiments.

Application of microwave irradiation in the synthesis of P-heterocycles

Phosphinic and phosphonic acids are useful intermediates and biologically active compounds which may be prepared from their esters, phosphinates and phosphonates, respectively, by hydrolysis or dealkylation. The hydrolysis may take place both under acidic and basic conditions, but the C-O bond may also be cleaved by trimethylsilyl halides. The hydrolysis of P-esters is a challenging task because, in most cases, the optimized reaction conditions have not yet been explored. Despite the importance of the hydrolysis of P-esters, this field has not yet been fully surveyed. In order to fill this gap, examples of acidic and alkaline hydrolysis, as well as the dealkylation of phosphinates and phosphonates, are summarized in this review.

The Hydrolysis of Phosphinates and Phosphonates: A Review

GRAPHICAL ABSTRACT ABSTRACT Bis(3-aminophenyl)phosphinic acid was synthesized as bis(3-ammoniophenyl)phosphinic acid dichloride with sequential converting of bis(3-nitrophenyl)phosphinic acid to the corresponding O-butyl-bis(3-nitrophenyl)phosphinate, and then reducing it with hydrogen under pressure and hydrolyzing of the resulting O-butyl-bis(3-aminophenyl)phosphinate with conc. HCl. Homo- and heteronuclear NMR (COSY, HSQC, and HMBC) experiments were used for the unambiguous attribution of the proton and carbon atom signals in the 1H and 13C NMR spectra of synthesized compounds.

Synthetic routes to bis(3-aminophenyl) phosphinic acid

A series of acyclic symmetric quaternary ammonium chlorides Me2(HOCH2CH2)N+(CH2CH2O)nR Cl– (n = 1, R = n-C9H19; n = 2, R = n-C6H13; n = 3, R = n-C3H7) was synthesized by alkylation of the corresponding tertiary amines Me2N(CH2CH2O)nR with ethylene chlorohydrin in a two-phase system, using water as a solvent. The tertiary amines were synthesized in a heterogeneous system organic phase—aqueous phase, using an aqueous solution of Me2NH and a solid alkali. The intermediate monoethers of ethylene, diand triethylene glycol were obtained in high yield via a phase-transfer alkylation in dioxane, using solid KOH. The proton and carbon atom signals in the NMR spectra of the synthesized amines and ammonium chlorides were assigned based on the data of heteronuclear correlations (1H, 13C).

Synthesis of acyclic quaternary ammonium compounds containing ω-alkoxyethyl and 2-hydroxyethyl substituents at the nitrogen atom

A facile method for the synthesis of β-functionalized ethyldiphenylphosphine oxides is developed based on readily available 2-phenoxyethyldiphenylphosphine oxide used as an equivalent of diphenylvi...

2-Phenoxyethyldiphenylphosphine oxide as an equivalent of diphenylvinylphosphine oxide in nucleophilic additions

Pentadentate bis[N-alkyl-N-(2-diphenylphosphinylethyl)]diglycolamides [Ph2P(O)CH2CH2N(R)· C(O)CH2]2O, where R Me, Bu, Oct, were synthesized by reaction of diglycolyl chloride with N-alkyl-N-(2-diphenylphosphinylethyl)amines Ph2P(O)CH2CH2NHR obtained by reacting diphenyl(2-phenoxyethyl)phosphine oxide with primary alkylamines in DMSO in the presence of an aqueous alkali. Structure of the prepared compounds was studied by 1H, 13C, and 31P NMR spectroscopy.

Novel Bis[N-alkyl-N-(2-diphenylphosphinylethyl)]diglycolamides: Synthesis and NMR Spectroscopy Studies

Homoand heteronuclear NMR experiments (COSY, HSQC, and HMBC) were used for the attribution of the proton and carbon atom signals in the 1H and 13C NMR spectra of N-(ωalkoxyethyl)-N-(2-hydroxyethyl-)N, N-dimethylammonium chlorides Me2(HOCH2CH2)N+(CH2CH2O)nRCl– (n = 1, R = C9H19, C12H25; n = 2, R = C6H13, C12H25; n = 3, R = C3H7) bearing either one, two or three ethylene glycol units in 12-, 15-, and 18-membered substituents at the nitrogen atom. Performed experiments unambiguously confirmed the structures of the ammonium chloride studied.

K. V. Tcarkova

Papers

Synthetic routes to bis(3-aminophenyl) phosphinic acid

Synthesis of acyclic quaternary ammonium compounds containing ω-alkoxyethyl and 2-hydroxyethyl substituents at the nitrogen atom

2-Phenoxyethyldiphenylphosphine oxide as an equivalent of diphenylvinylphosphine oxide in nucleophilic additions

Novel Bis[N-alkyl-N-(2-diphenylphosphinylethyl)]diglycolamides: Synthesis and NMR Spectroscopy Studies

Structures and NMR spectra of N-(ω-alkoxyethyl)N-(2-hydroxyethyl)-N, N-dimethylammonium chlorides