N-Substituted tetrahydro-1,3-oxazines and oxazolidines. 1. A new version of the Mannich reaction involving amino alcohols

A new version of the Mannich reaction involving amino alcohols (3-aminopropan-1-ol and aminoethanol) was developed. These compounds react with formaldehyde and CH or NH acids to give N-substituted tetrahydro-1,3-oxazines or oxazolidines.     

Thermodecomposition ofo-benzoquinone complexes of transition metals

Thermodecomposition of 3,5- and 3,6-di-tert-butyl-o-benzoquinone complexes of Cu, Fe, Co, Cr, Mo, and W has been investigated in the solid phase by the thermogravimetric method. The relative stability of a series of complexes has been determined from the temperatures at which their decomposition begins. Detachment of a neutral electron-donor ligand takes place in the first stage. Detachment of ano-quinone ligand and decomposition of theo-benzoquinone formed occur in the next stage. Thermodecomposition of Fe, Co, Cr, Mo, and W complexes gives oxides or carbides, while copper complexes decompose to pure metal.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 327–329, February, 1994.     

Postmetallocene lanthanide-hydrido chemistry: A new family of complexes [{Ln{(Me3Si)2NC(NiPr)2}2(mu-H)}2] (Ln = Y, Nd, Sm, Gd, Yb) supported by guanidinate ligands-synthesis, structure, and catalytic activity in olefin polymerization

The new family of Lewis base free hydrido complexes of rare-earth metals supported by guanidinate ligands [{Ln{(Me3Si)2NC(NiPr)2}2(mu-H)}2] (Ln = Y, Nd, Sm, Gd, Yb) was synthesized and structurally characterized. Single-crystal X-ray and solution NMR studies revealed that these complexes are dimeric in both solid state and in [D6]benzene. The dimeric hydrido complexes can adopt eclipsed (Nd, Sm, Gd) or staggered (Y, Yb, Lu) conformations depending on the metal-atom size. Catalytic activity of these [{Ln{(Me3Si)2NC(NiPr)2}2(mu-H)}2] complexes in the polymerization of ethylene, propylene, and styrene has been investigated. Complexes of Sm and Y have high catalytic activity in ethylene polymerization (1268 and 442 g mmol(-1) atm(-1) h(-1), respectively).     

New N-nitrosoamines. 2. Transformations of tetrahydro-1,3-oxazines into nitrates of N-nitrosoamino alcohols

The reactions of HNO₃ with tetrahydro-1,3-oxazines 1a—c produced by aminomethylation of diketopiperazine, isatin, and succinimide, respectively, afforded nitrates of amino alcohols [RCH₂NH₂(CH₂)₃ONO₂]⁺NO₃ ^– (4a—c) whose subsequent N-nitrosation (NaNO₂, AcOH) gave nitrates of N-nitrosoamino alcohols RCH₂N(NO)(CH₂)₃ONO₂ (5a—c). The structures of compound 5b,c were established by X-ray diffraction analysis.     

New N-nitrosoamines. 1. Synthesis and nitrosative cleavage of the Mannich bases derived from nitrogen-containing heterocycles and primary aliphatic amines

The reactions of isatin, benzotriazole, and succinimide with formaldehyde and methylamine yield monoamines RCH₂N(Me)CH₂R and methylenediamines RCH₂N(Me)CH₂N(Me)CH₂R. The use of ethylenediamine as the amino component affords N,N"-disubstituted imidazolidines, while the reactions with 3-aminopropan-1-ol give N-substituted tetrahydro-1,3-oxazines. RCH₂NBuⁱ ₂ was obtained from succinimide, formaldehyde, and diisobutylamine. Nitrosative cleavage of the amines obtained was studied; it was shown that monoamines and methylenediamines give N-nitrosoamines RCH₂N(NO)Me, which were structurally characterized by X-ray diffraction analysis. RCH₂NBuⁱ ₂ affords diisobutylnitrosamine, while imidazolidines transform into dinitroso compounds RCH₂N(NO)CH₂CH₂N(NO)CH₂R.     

Synthesis and structural study of 4,6-diazido-2-(2,2,2-trinitroethylamino)-1,3,5-triazine

Russian Chemical Bulletin - A method for synthesis of 2-(2,2,2-trinitroethylamino)-4,6-diazido-1,3,5-triazine from 2-amino-4,6-diazido-1,3,5-triazine was elaborated. The molecular and crystal...     

Cytostatic action of triazole and oxazolidinone derivatives

We synthesized a number of derivatives of 1,2,3-benzotriazole, 1,2,4-triazole, and oxazolidine-2-one derivatives, among which compounds suppressing the growth of the tumor cells HeLa and H1299 were revealed. The studies of the effect of these compounds on the cell cycle and activity of caspase dependent degradation of poly(ADP-ribose) polymerase showed that these compounds at the IC₅₀ doses exhibit cytostatic effect on tumor cells. In the MCF7 cells, these compounds induce an increase in expression of the tumor suppressor p53.     

Oxidation of bis(triethylgermyl)mercury in the presence of tert-butyl alcohol

The oxidation of bis(triethylgermyl)mercury by oxygen in the presence of tert-butyl alcohol has been investigated. It has been shown that the dependence of the rate of oxidation on the value of n ¹ for tert-butyl alcohol within the range n = 0–12 is similar to that for unassociated ligand-catalysts. On increasing n further (from 12 to 60) increasing association of the alcohol causes a drastic increase in the reaction rate relative to the increase in n due to the higher catalytic activity of the high molecular weight associated species.     

Preparation of quaternary ammonium salts with a perhydroimidazo[1,5-c]oxazolium molecular skeleton

Russian Chemical Bulletin -