Ethyl 3,3-diamino-2-(2-p-tolylpyrimidin-4-yl)acrylate,a new representative of hetarylketene aminals

A new representative of hetarylketene aminals, ethyl 3,3-diamino-2-(2-p-tolylpyrimidin-4-yl)acrylate, was synthesized by the reaction ofp-toluamidine with the condensation product of dimethylformamide dimethyl acetal and the difluoroboron chelate of acetyl(ethoxycarbonyl)ketene (N-benzoyl)aminal. This synthesis is an example of pyrimidine ring assembly using the methodology based on transformations of chelate complexes.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1638–1640, September, 1994.This research was partially supported by the International Science Foundation (Grant No. M5QOOO).     

Chelate synthesis of 2,2′-bipyridin-4-one

A method for the synthesis of 2,2′-bipyridin-4-one from 4-amino-4-(2-pyridyl)-but-3-en-2-onevia its diphenylboron, chelates was proposed. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2071–2073, November, 1997.     

Molecular and crystal structure of the intracomplex 2-[(dibutylboryloxy)(Butyl) borylamino]-4-methylpyridine with boron atoms of differing hybridization in the chelate ring

X-ray diffraction has been used to establish the crystalline and molecular structure of the intracomplex 2-[(dibutylboryloxy)(butyl)borylamino]4-methylpyridine. In the crystal, the molecule forms weak intermolecular N(H)...O hydrogen bonds. The bicyclic portion of the molecule is nearly planar. From the bond lengths in the ring, which incorporates boron atoms of differing hybridization (sp³ and sp²), it follows that delocalization of electron density extends only over the amidine fragment. Quantum chemical calculations (MO LCAO, version CNINDO/2) show that the electron density at the endocyclic nitrogen of the aminopyridine system coordinated with boron is lower than that at the endocyclic nitrogen of the aminopyridine.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 173–177, January, 1991.     

Synthesis of N-(5-tetrazolyl)amidines from 5-aminotetrazole and nitriles using organoboranes

Conclusions A method has been proposed for the synthesis of N-(5-tetrazolyl)amidines from 5-amino-tetrazole, nitriles, and organoboranes through boron chelate compounds, namely, dialkyl-boryl[N-(5-tetrazolyl)amidinates].Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2622–2624, November, 1987.     

Structures of boron chelates of mono- and diacylketene aminals

The molecular and crystal structures of diphenylboron chelates of acetylketeneN-benzoylaminal and 2-(N-benzoyl)diaminomethylene-4-dimethylaminomethylenecyclohexane-1,3-dione and the structure of the difluoroboron complex of diacetylketeneN-benzoylaminal were established. It was found that the aminovinylcarbonyl fragment of the ligand is involved in the formation of a boron-containing ring. A delocalized -electron system over the NCCCO fragment of the chelate ring is characteristic of the molecules studied both in crystals and solutions.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2541–2546, October, 1996.     

Synthesis of N-unsubstituted ketene aminals from β-ketocarboxylic esters and cyanamide

The interaction of cyanamide with -ketocarboxylic esters in the presence of Ni(acac)₂ affords N-unsubstituted aminals of acyl(alkoxycarbonyl)ketenes.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 419–421, February, 1993.     

5-Acyl-4-amino-2-phenyl-1,3-oxazin-6-ones

Intramolecular cyclization of acyl(ethoxycarbonyl)keteneN-benzoylaminals in boiling Ph₂O gives 5-acyl-4-amino-2-phenyl-1,3-oxazin-6-ones.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1322–1323, July, 1995.This study was financially supported by the Russian Foundation for Basic Research (Grant No. 94-03-08964).     

Thioboronation of acetonitrile

Conclusions The esters of dialkylthioboronic acids add to acetonitrile with the formation of crystalline adducts, which when heated decompose to the starting materials.     

Complexes of sodium and lithium borohydrides with macrocyclic polyethers

A method for the synthesis of complexes of sodium and lithium borohydrides with crown ethers is proposed. The complexes of sodium borohydride with benzo-15-crown-5, 4′-aminobenzo-15-crown-5, dibenzo-18-crown-6, and diaza-18-crown-6 and the complexes of lithium borohydride with benzo-15-crown-5 and dibenzo-18-crown-6 are synthesized. These complexes can be used for the preparation of hydrogen in their reactions with methanol. The complex formation does not affect the purity of hydrogen formed.