ChemInform Abstract: Trimethylsilyl Derivatives of Benzoic 2,2‐Dimethylhydrazides.

Kalikhman, I. D.; Bannikova, O. B.; Волкова, Л. И.; Gostevskii, B. A.; Yushmanova, T. I.; Лопырев, В. А.; Воронков, М. Г.

doi:10.1002/chin.198831207

Cited by 6 publications

(14 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Chlorocyclohexylbis[ N ‘ -(dimethylamino)benzimidato- N,O ]silicon(IV) (1a) . To a solution of 3d (1.156 g, 4.89 mM) in 10 mL of n -hexane was added 2a (0.732 g, 3.36 mM), and the mixture was stirred for 1 h at RT. The volatiles were removed under vacuum and the residue washed with 10 mL of n -hexane, leaving a white powder of 1a (0.99 g, 2.10 mM, 88%) mp 131−2 °C.…”

Section: Methodsmentioning

confidence: 99%

Complete Intermolecular Ligand Crossover in Hexacoordinate Silicon Dichelates. Establishment of a Ligand Priority Order

et al. 2007

View full text Add to dashboard Cite

Hexacoordinate silicon dichelates undergo three unique intermolecular chelate exchange reactions: complete ligand transfer from dichelates to trichlorosilanes, which is formally equivalent to interchange of monodentate ligands between dichelate and ZSiCl3, controlled by a ligand priority order; bidentate ligand interchange between dichelate and trimethylsilyl-hydrazide precursor; complete chelate crossover between different dichelates.

show abstract

Section: Methodsmentioning

confidence: 99%

Complete Intermolecular Ligand Crossover in Hexacoordinate Silicon Dichelates. Establishment of a Ligand Priority Order

et al. 2007

View full text Add to dashboard Cite

show abstract

“…O-trimethylsilylated 1,1-dimethyl-2-acylhydrazines ( 1b , c ) were prepared as described previously 1,33 and distilled under reduced pressure. The boiling points were as follows: 1b , 80−82 °C (0.8 mmHg), lit 33a. bp 110−112 °C (2 mmHg); 1c , 70−73 °C (30 mmHg), lit 33b.…”

Section: Methodsmentioning

confidence: 99%

“…The boiling points were as follows: 1b , 80−82 °C (0.8 mmHg), lit 33a. bp 110−112 °C (2 mmHg); 1c , 70−73 °C (30 mmHg), lit 33b. bp 41 °C (10 mmHg).…”

Section: Methodsmentioning

confidence: 99%

Irreversible Rearrangement in Hexacoordinate Silicon Complexes: From Neutral Bis(N→Si) Chelates to Mono(N→Si) Zwitterionic λ⁶-Silicates

et al. 2000

View full text Add to dashboard Cite

The reaction of (chloromethyl)trichlorosilane (7) with O-trimethylsilylated N,N-dimethylhydrazides yields initially under kinetic control, in nearly quantitative yields, a neutral hexacoordinate bis(NfSi) chelate, bis(N-(dimethylamino)acylimidato-N,O)chloro(chloromethyl)silicon(IV) (8a-c). Upon heating, the octahedral complexes 8 are quantitatively and irreversibly converted to the isomeric hexacoordinate chelates zwitterionic λ 6 -silicates 9a-c, (N-(dimethylamino). This molecular rearrangement is rather unusual, since it involves chelatering expansion from the common five-membered ring to a six-membered ring in the thermodynamically favored product 9. 8b and 9b were characterized by X-ray crystal analyses and in solution by their 1 H, 13 C, and 29 Si NMR spectra. The analogous compounds 8a,c and 9a,c were characterized by the respective analogy of their NMR spectra. Both 8b and 9b have slightly distorted octahedral geometries around the central silicon atom. Both series of chelates 8 and 9 undergo ligand-site exchange processes, observed by the coalescence of signals due to diastereotopic N-methyl and/or CH 2 groups. Each compound (of both series) undergoes two consecutive rate processes: in 8 this sequence of exchange processes is analogous to previously reported stereomutations through a bicapped-tetrahedral intermediate or transition state; in 9 the first (lower barrier) process is a nitrogen-silicon dissociationrecombination, and the high-barrier process is an inversion of configuration at the silicon center.We have recently utilized the reaction of O-(trimethylsilyl)-N,N-dimethylhydrazides (1) with polyhalosilanes as a convenient method for the synthesis of a variety of different penta-and hexacoordinate silicon complexes with NfSi coordination (eq 1). 1-9 1 functions as a precursor for five-membered NfSi chelate rings.On the other hand, when 1 was allowed to react with (chloromethyl)dimethylchlorosilane (4; eq 2), OfSi coordinated complexes with five-and six-membered chelate cycles (6 and 5, respectively) were obtained. 10-13 † Ben-Gurion University. Kalikhman, I.; Krivonos, S.; Stalke, D.; Kottke, T. J. Am. Chem. Soc. 1998, 120, 4209. (7) Mozzhukhin, A. O.; Antipin, M. Yu.; Struchkov, Yu. T.; Gostevskii, B. A.; Kalikhman, I. D.; Pestunovich, V. A.; Voronkov, M. G. Bannikova, O. B.; Petuchov, L. P.; Pestunovich, V. A.; Voronkov, M. G. Dokl. Akad. Nauk SSSR 1986, 287, 870. (11) Kalikhman, I. D.; Pestunovich, V. A.; Gostevskii, B. A.; Bannikova, O. B.; Voronkov, M. G. J. Organomet. Chem. 1988, 338, 169. (12) Macharashvili, A. A.; Shklover, V. E.; Struchkov, Yu. T.; Gostevskii, B. A.; Kalikhman, I. D.; Bannikova, O. B.; Voronkov, M. G.; Pestunovich, V. A.

show abstract

“…A mixture of 1.22 g (5.15 mmol) of 4a and 0.266 g (2.31 mmol) of MeHSiCl 2 ( 5 ) in 5 mL of trichloromethane was stirred at room temperature for 2 h. The volatiles were removed under reduced pressure (0.1 mmHg), and the white solid residue was recrystallized from 15 mL of n -hexane; 0.654 g was obtained (76%). Mp: 85−86 °C.…”

Section: Methodsmentioning

confidence: 99%

“…A mixture of 0.892 g (3.77 mmol) of 4a and 0.311 g (1.76 mmol) of PhHSiCl 2 ( 6 ) in 5 mL of trichloromethane was stirred at room temperature for 24 h. The volatiles were removed under reduced pressure (0.1 mmHg), and the resulting viscous liquid was crystallized from 10 mL of n -hexane. The white solid was washed twice with n -hexane and dried to yield 0.605 g (79%).…”

Section: Methodsmentioning

confidence: 99%

Reversible Neutral Dissociation of the N−Si Dative Bond in Hexacoordinate Hydrido Complexes of Silicon

et al. 2008

View full text Add to dashboard Cite

Hexacoordinate silicon dichelates with hydrido and methyl monodentate ligands were prepared by transsilylation. The temperature-dependent 29 Si NMR spectra of toluene-d 8 or CDCl 3 solutions provide evidence for a reversible, neutral dissociation of the dative N-Si bond, accompanied by a shift of the 29 Si resonance from high field (hexacoordinate) to lower field (pentacoordinate) with increasing temperature. When a phenyl group is attached directly to silicon (replacing methyl), the N-Si dissociation is prevented, presumably due to electron withdrawal by the phenyl. Two of the silicon complexes were characterized by crystallographic analysis. Quantum chemical calculations at the RB3LYP/6-31G(d) level confirm the stability of an N-Si dissociated species (1.03 kcal mol -1 lower in energy than the hexacoordinate dichelate) and rule out the alternative possibility of an O-Si zwitterionic dissociation, thus supporting the mechanism suggested by the experimental results.

show abstract

ChemInform Abstract: Trimethylsilyl Derivatives of Benzoic 2,2‐Dimethylhydrazides.

Abstract: ChemInform Abstract Silylation of the hydrazides (I) with trimethylsilyl chloride (II) takes place exclusively at the oxygen atom, producing the hydrazonic acid esters (III).

Cited by 6 publications

References 0 publications

Complete Intermolecular Ligand Crossover in Hexacoordinate Silicon Dichelates. Establishment of a Ligand Priority Order

Complete Intermolecular Ligand Crossover in Hexacoordinate Silicon Dichelates. Establishment of a Ligand Priority Order

Irreversible Rearrangement in Hexacoordinate Silicon Complexes: From Neutral Bis(N→Si) Chelates to Mono(N→Si) Zwitterionic λ⁶-Silicates

Reversible Neutral Dissociation of the N−Si Dative Bond in Hexacoordinate Hydrido Complexes of Silicon

Contact Info

Product

Resources

About

ChemInform Abstract: Trimethylsilyl Derivatives of Benzoic 2,2‐Dimethylhydrazides.

Abstract: ChemInform Abstract Silylation of the hydrazides (I) with trimethylsilyl chloride (II) takes place exclusively at the oxygen atom, producing the hydrazonic acid esters (III).

Cited by 6 publications

References 0 publications

Complete Intermolecular Ligand Crossover in Hexacoordinate Silicon Dichelates. Establishment of a Ligand Priority Order

Complete Intermolecular Ligand Crossover in Hexacoordinate Silicon Dichelates. Establishment of a Ligand Priority Order

Irreversible Rearrangement in Hexacoordinate Silicon Complexes: From Neutral Bis(N→Si) Chelates to Mono(N→Si) Zwitterionic λ6-Silicates

Reversible Neutral Dissociation of the N−Si Dative Bond in Hexacoordinate Hydrido Complexes of Silicon

Contact Info

Product

Resources

About

Irreversible Rearrangement in Hexacoordinate Silicon Complexes: From Neutral Bis(N→Si) Chelates to Mono(N→Si) Zwitterionic λ⁶-Silicates