V. A. Pestunovich

The reaction of N-trimethylsilyl-amides and -lactams with dimethyl(chloromethyl)chlorosilane. Kinetically controlled formation of (NSi) chelate intermediates, O-[(dimethylchlorosilyl)methyl]imidates and their rearrangement to final(OSi) chelate N-[(dimethylchlorosilyl)methyl]amides and lactams

The multistage character of the reaction of dimethyl(chloromethyl)chlorosilane (I) with N-trimethylsilyl-amides and -lactams (II) was shown by NMR monitoring. Interaction of the reactants starts with transsilylation, leading to Me3SiCl and the corresponding N-[dimethyl(chloromethyl)silyl]amide or -lactam (III). The second stage, intramolecular (dimethylchlorosilyl)methylation of unstable III, proceeds in two directions. A kinetically controlled transformation of III affords previously unknown O-(dimethylchlorosilyl)methylated intermediates, O-[(dimethylchlorosilyl) methyl]imidates (IV) containing a hypervalent ClSiN bond. The already known products, (OSi) chelate N-[(dimethylchlorosilyl)methyl]amides (V), arise from the reaction carried out under thermodynamic control. The same compounds are also formed via the Chapman rearrangement of the intermediates (IV).

Direct evidence of the existence of organic derivatives of pentacoordinated silicon with the Si ← Cl coordinate bond. Molecular structure of chloro [1-{1,1-dimethyl-2-(4′methoxybenzoyl}hydrazonium) methyl] dimethylsilane

Abstract An X-ray study of chloro[1-{1,1-dimethyl-2-(4′methoxybenzoyl)hydrazonium} methyl]dimethylsilane (I) has been carried out ( R = 0.035 for 2800 reflections). The Si atom, which has a trigonal-bipyramidal [4 + 1] coordination with the O and Cl atoms in axial positions (Si–O 1.788(1) A, SiCl 2.624(1) A, is markedly displaced from the equatorial plane towards the oxygen atom (Δ Si 0.178 A), which confirms that there is a coordinate bond between the silicon atom and chloride ion.

SYNTHESIS AND STRUCTURE OF 1- AND 2-ISOMERS OF (TRIMETHOXYSILYLMETHYL)- AND (SILATRANYLMETHYL)BENZOTRIAZOLE

We have synthesized 1- and 2-(trimethylsilylmethyl)- and 1- and 2-(trimethoxysilylmethyl)benzotriazoles by reaction of 1,2,3-benzotriazolylsodium with trimethyl- or trimethoxy(chloromethyl)silane. We obtained 1- and 2-(silatranylmethyl)benzotriazoles by transesterification of the latter with triethanolamine.

Molecular Structure of (O→Si)Methyl N-Methyl-N-(trifluorosilylmethyl)carbamate in Crystal and in Solution

Developing the studies on the intracomplex organic derivatives of pentacoordinate silicon (dragonoids) corresponding to the general formula XC (= O ) YCH 2 SiF 3 (X is an organic substituent, Y = O, S, NR, CH 2 , etc.) [1], we have studied the crystal and molecular structure and behavior in solution of a new representative of this class with X = MeO and Y = NMe, (O Si)methyl N -methylN -(trifluorosilylmethyl)carbamate MeOC (= O ) NMeCH 2 SiF 3 ( I ). The molecular structure of its analogues, intracomplex (O Si) N -methylN -(trifluorosilylmethyl)acetamide MeC (= O ) NMeCH 2 SiF 3 ( II ) and (O Si) N methylN -(trifluorosilylmethyl)trifluoroacetamide F 3 CC (= O ) NMeCH 2 SiF 3 ( III ), was established earlier [2, 3]. Even earlier, the molecular structure of (O Si) N -methylN -(methyldifluorosilylmethyl)acetamide MeC (= O ) NMeCH 2 SiMeF 2 ( IV ) [2, 4], which also belongs to the class of dragonoids, was studied. (O Si)Methyl N -methylN -(trifluorosilylmethyl)carbamate ( I ) was obtained according to scheme (1) by the reaction of methyl chloroformate with ( N methylamino)methyltriethoxysilane followed by fluorination of the resulting carbamate ( V ) with boron trifluoride etherate:

Synthesis of Si-containing cyclic ureas

Abstract1,3-Bis[(triethoxysilyl)methyl]tetrahydropyrimidin-2-one and 1,3-bis[(dimethoxysilyl)methyl]tetrahydro-pyrimidin-2-one have been synthesized on interacting urea with N,N′-bis(silylmethyl)propylenamines (EtO)3−nMenSiCH2NH(CH2)3NHCH2SiMen(OEt)3−n (n = 0, 2). Their interaction with boron trichloride has been studied. The structures of all the compounds synthesized have been demonstrated by multinuclear NMR spectroscopy.

N-substituted (3-aminopropyl)trifluorosilanes and [3-(trifluorosilyl)propyl]diorganylamine-trifluoroboranes

The possibility of the formation of an intramolecular N ,Si coordination bond in (3-aminopropyl)triethoxysilane and its N-substituted derivatives has been discussed previously [1-4]. The likelihood of the existence of an N ,. Si bond in (3-aminopropyl)trifluorosilane and its N-substituted derivatives is beyond doubt because of the high electrophilicity of the silicon atom linked to the three fluorine atoms. However, such compounds have not yet successfully prepared.