The nmr study and cndo/2 molecular orbital calculation of silacyclobutanes

Krapivin, A. M.; Mägi, Μ.; Svergun, V. I.; Zaharjan, R.Z.; Babich, É. D.; Ушаков, Н. В.

doi:10.1016/s0022-328x(00)82875-2

Cited by 56 publications

(11 citation statements)

References 33 publications

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“…The coupling constant ( 29 Si-13 C α ) in tetracoordinate 1,1-diethoxysilacyclohexane is the intermediate value (J Si-C = 55 Hz). 13 Such change of the coupling constant of silicon atom with subsituents well agree with the change of scharacter of the bond with axial and equatorial substituents in TBP. …”

Section: Methodssupporting

confidence: 72%

“…At room temperature reactions would not proceed, whereas at 60 o C the cleavage of silacyclobutane Si-C bond in the starting compounds and products suppressed the formation of the target 1 and 2. NMR data of 1 and 2 in solution are given in the At ambient temperature, a silicon pentacoordination of 1 and 2 manifests itself in greater downfield 13 C shift of the carbon atoms attached to silicon (6.5 and 4.9 ppm, respectively) as compared to that of the model tetracoordinate silicon compound, 1,1-diethoxysilacyclobutane (lit., 13 20.8 ppm). A single resonance was observed for the Si-CH 2 carbons at this temperature.…”

Section: Methodsmentioning

confidence: 99%

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Synthesis and NMR study of intramolecular silacyclobutane complexes: 8-aza-5,11-dioxa-4-silaspiro[3,7]undecane and 8-methyl-8-aza-5,11-dioxa-4-silaspiro[3,7]undecane

Pestunovich¹,

Lazareva²,

Albanov³

et al. 2006

Arkivoc

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The intramolecular silacyclobutane complexes with pentaacoordination at silicon, 8-aza-5,11-dioxa-4-silaspiro[3,7]undecane and 8-methyl-8-aza-5,11-dioxa-4-silaspiro[3,7]undecane, were synthesized by reacting 1,1-dimethoxy-or 1,1-bis(diethylamino)silacyclobutanes with the corresponding diethanolamines. The existence of (Si N) pentaacoordination at silicon was deduced from the pronounced upfield 29 Si and downfield 13 C NMR shifts as well as from the low temperature 13 C NMR study of their dynamic behavior in solution that proved complexes to appear as two isomers with coalescence barriers of 11.5 kcal/mol and 12.9 kcal/mol for 1 and 2, respectively.

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Section: Methodssupporting

confidence: 72%

Section: Methodsmentioning

confidence: 99%

Synthesis and NMR study of intramolecular silacyclobutane complexes: 8-aza-5,11-dioxa-4-silaspiro[3,7]undecane and 8-methyl-8-aza-5,11-dioxa-4-silaspiro[3,7]undecane

Pestunovich¹,

Lazareva²,

Albanov³

et al. 2006

Arkivoc

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“…These results suggest that the high moisture sensitivity of 3 is probably due not to ring strain but to the strong dipole moment, which increases the electrophilicity of the Si atom, facilitating its attack by H 2 O. This idea was supported by 29 Si NMR data, where the peak of 3a (3.99 ppm) was more upfield than that of 7 (18.4 ppm) (Figure b), consistent with Krapivin’s observation that peaks move more upfield as the positive charge on the Si atom increases …”

Section: Resultssupporting

confidence: 82%

3-Silaazetidine: An Unexplored yet Versatile Organosilane Species for Ring Expansion toward Silaazacycles

Wang

Zhou

et al. 2021

J. Am. Chem. Soc.

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Small-ring silacycles are important organosilane species in main-group chemistry and have found numerous applications in organic synthesis. 3-Silaazetidine, a unique small silacycle bearing silicon and nitrogen atoms, has not been adequately explored due to the lack of a general synthetic scheme and its sensitivity to air. Here, we describe that 3-silaazetidine can be easily prepared in situ from diverse air-stable precursors (RSO2NHCH2SiR1 2CH2Cl). 3-Silaazetidine shows excellent functional group tolerance in a palladium-catalyzed ring expansion reaction with terminal alkynes, giving 3-silatetrahydropyridines and diverse silaazacycle derivatives, which are promising ring frameworks for the discovery of Si-containing functional molecules.

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“…Monomers M2, 27 M1, 28 M4 and М5, 18 M6, 29 М7 30 used for the syntheses of polymers and copolymers and monomers with unsaturated groups M8 31 and M9 32 were obtained by known procedures.…”

Section: Methodsmentioning

confidence: 99%

New polysilalkylenes: synthesis and gas-separation properties

et al. 2004

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A series of polysiltrimethylenes with different substituents at the silicon atom, as well as new polydimethylsilmethylene, were synthesized by the ring opening polymerization of the corresponding sila and disilacyclobutanes. For the first time, the copolymerization of dimethylsila and tetramethyldisilacyclobutanes was carried out with formation of permethyl silalkylene elastomers containing a controlled number of silmethylene and siltrimethylene units in the main chain. Permeability coefficients of n alkanes C 1 -C 4 were measured for the prepared silalkylene homopolymers and copolymers by mass spectrometric and barometric techniques. An analysis of the permeability, solubility, and diffusion coefficients indicated that the separation of hydrocarbons proceeded according to a solubility controlled mechanism. Polysilalkylenes with various structures of radicals at the Si atom were applied onto the surface of porous hollow fibers. The study of gas separation parameters of the obtained composite membranes showed that they dramatically depended on the type of substituents at the Si atom. The series of polypermethylsilalkylenes are promising as membrane materials for the separa tion of hydrocarbon gases.

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The nmr study and cndo/2 molecular orbital calculation of silacyclobutanes

Cited by 56 publications

References 33 publications

Synthesis and NMR study of intramolecular silacyclobutane complexes: 8-aza-5,11-dioxa-4-silaspiro[3,7]undecane and 8-methyl-8-aza-5,11-dioxa-4-silaspiro[3,7]undecane

Synthesis and NMR study of intramolecular silacyclobutane complexes: 8-aza-5,11-dioxa-4-silaspiro[3,7]undecane and 8-methyl-8-aza-5,11-dioxa-4-silaspiro[3,7]undecane

3-Silaazetidine: An Unexplored yet Versatile Organosilane Species for Ring Expansion toward Silaazacycles

New polysilalkylenes: synthesis and gas-separation properties

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