M. M. Kabachnik

Reactions of Hydrophosphoryl Compounds with Schiff Bases in the Presence of CdI2

The reaction of hydrophosphoryl compounds with aldimines and ketimines in the presence of catalytic amounts of cadmium iodide was investigated. A simple preparative method for the synthesis of α-aminophosphonates, phosphinates, and tertiary phosphine oxides was developed.

Catalytic synthesis of α-hydroxyphosphonates

Reactions of carbonyl compounds of aliphatic, aromatic, and heteroaromatic series with dialkyl phosphites in the presence of DBN were studied under microwave irradiation.

Microwave-Assisted Reactions of Schiff Bases with Diethyl Phosphonate in the Presence of CdI2

The reaction of diethyl phosphonate with Schiff bases derived from aldehydes and ketones in the presence of cadmium iodide is strongly accelerated by microwave irradiation, and the corresponding α-aminophosphonates are formed in high yields.

Synthesis of α-aminophosphonates under conditions of phase-transfer catalysis

An easy preparative synthesis of α-aminophosphonates by reaction of azomethines with diethyl phosphite under conditions of phase-transfer catalysis was developed.

Phosphorylation of Amino(aryl)methylphosphonates by the Atherton—Todd Reaction

We were the first to perform phosphorylation of amino(aryl)methylphosphonates having a primary amino group under the Atherton–Todd reaction conditions. The reactions of amino(aryl)methylphosphonates Ia–Ie with diethyl phosphonate and carbon tetrachloride in the presence of triethylamine were carried out at room temperature, on heating at 110oC, and under microwave irradiation. The reactions under microwave irradiation were complete in 30–40 min, and the corresponding N-(α-phosphoryl)amidophosphates IIa–IIe were obtained in 63–93% yield. No reaction occurred at room temperature, whereas after heating for 24 h at 110°C compounds IIa–IIe were isolated in poor yields (15–20%) due to predominant formation of pyrophosphate on prolonged heating. The product structure was confirmed by their H, C, and P NMR spectra and elemental analyses. Compounds IIa–IIe displayed in the P NMR spectra doublet signals at δP 6.2–6.8 and 22.2–22.6 ppm with coupling constants of 40.2–42.7 Hz. In the H NMR spectra of IIa–IIe, the NCH proton characteristically resonated at δ 4.4–4.6 ppm, and the corresponding carbon signal appeared in the C NMR spectra as a doublet at δC 51.3–53.8 ppm (JPC = 153–156 Hz). Diethyl aryl(diethoxyphosphorylamino)methylphosphonates IIa–IIe (general procedure). Carbon tetrachloride, 20 mmol (3.08 g, 2.11 ml), triethylamine, 15 mmol (1.52 g, 1.08 ml), and aminophosphonate Ia–Ie, 10 mmol, were added in succession to 10 mmol (1.38 g, 1.29 ml) of diethyl phosphonate. The reaction was carried out in an open vessel under microwave irradiation (102 W, 115°C). The precipitate of triethylamine hydrochloride was filtered through a glass filter, the filtrate was cooled and evaporated on a rotary evaporator, and the residue was subjected to column chromatography on silica gel using chloroform–methanol (50 : 1) as eluent.

Synthesis of optically active phosphonamino acids esters at microwave assistance

A preparative synthesis was developed for phosphonamino acids esters proceeding from natural amino acids with the use of microwave assistance. A series of phosphonamino acids esters was prepared from optically active natural α-amino acids.

Preparation of arylphosphonates by the reaction of aryl halides with tris(trimethylsilyl) phosphite under homogeneous catalysis conditions

The reaction of tris(trimethylsilyl) phosphite with aryl bromides under homogeneous catalysis conditions gives bis(trimethylsilyl)arylphosphonates. The desilylation of these phosphonate products with methanol leads to arylphosphonic acids.

Synthesis of new amidophosphates containing an adamantyl fragment under microwave irradiation

The reaction of amines containing an adamantly fragment with diethyl phosphite in tetrachloromethane in the presence of triethylamine was studied under the microwave irradiation.

SYNTHESIS AND SOME PROPERTIES OF PHOSPHORUS-SUBSTITUTED AZOMETHINES

A series of phosphorus(iii)-substituted azomethines and enamines were synthesized by the reaction of lithium salts of aldimines and ketimines with derivatives of phosphorus(iii) acids. Some properties of the compounds synthesized were studied.

Synthesis of aryl- and hetarylphosphonates

The reaction of tris(trimethylsilyl) phosphite with aryl or hetaryl halides under homogeneous catalysis conditions gave bis(trimethylsilyl)phosphonates. Treatment of these products with methanol gave the corresponding arylor hetarylphosphonic acids in quantitative yield.