Silicon-carbon unsaturated compounds.  25.  Synthesis and photochemical behavior of bis(disilanyl)benzenes

Ishikawa, Mitsuo; Sakamoto, H.; Kanetani, Fujio; Minato, Akio

doi:10.1021/om00114a005

Cited by 27 publications

(4 citation statements)

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“…Transition metal silylene complexes have been the target of numerous synthetic investigations over many years since these compounds are expected to mediate useful transformations of organosilicon species. , In fact, a number of stoichiometric and catalytic reactions based on transition metal reagents appear to involve silylene complexes as intermediates. − Considerable progress toward understanding the properties of silylene complexes has been made in recent years. In 1987, closely related base adducts containing tetrahedral silicon centers, of the type L n MSiR 2 (donor), were described .…”

Section: Introductionmentioning

confidence: 99%

Reversible Cycloaddition of Isocyanates to Ruthenium Silylene Complexes

and

Tilley

1997

J. Am. Chem. Soc.

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Reactions of ruthenium silylene complexes of the type [Cp*(PMe3)2RuSiR2]+ with unsaturated compounds were investigated. Nonpolar, unsaturated substrates such as ethylene, acetylene, and 2-butyne do not react with [Cp*(PMe3)2RuSiR2]B(C6F5)4 (1a, R = Me; 1b, R = Ph). However, methyl isocyanate inserts into an Si−S bond of the silylene complex [Cp*(PMe3)2RuSi(STol)2][BPh4] (5) to give the 1,2-dipolar addition product {Cp*(PMe3)2RuSi(STol)[η2−O(MeN)C(STol)]}[BPh4] (6a) in 87% yield. This product was characterized by X-ray crystallography as possessing a base-stabilized silylene ligand with thiolate and thiocarbamate substituents. Compound 1a reacts with methyl and phenyl isocyanate to give the 2 + 2 R = Me; 8, R = Ph). The analogous triflate R = Ph; 10, R = Me) were prepared by reaction of the appropriate ruthenium silyls Cp*(PMe3)2RuSiR2OTf with methyl isocyanate. Heating 9 to 100 °C in toluene resulted in dissociation of the isocyanate and regeneration of the triflate Cp*(PMe3)2RuSiPh2OTf. Competition reactions of various para-substituted phenyl isocyanates with 1b show that the rate of cycloaddition increases with the electron-donating ability of the incoming isocyanate. This is consistent with a stepwise cycloaddition mechanism involving initial coordination of the isocyanate nitrogen atom to the Lewis acidic silylene silicon atom.

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Section: Introductionmentioning

confidence: 99%

Reversible Cycloaddition of Isocyanates to Ruthenium Silylene Complexes

and

Tilley

1997

J. Am. Chem. Soc.

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“…48,49 In relation to the photoreactions of the compounds with bis(disilanyl) group similar to the compound † This paper is dedicated to Professor Sunggak Kim on the occasion of his honorable retirement. 1, Ishikawa et al 50 found the photolysis of 1,2-, 1,3-, and 1,4-bis(disilanyl)benzene in the presence of isobutene gave 2-(iso- Irradiation of 1 in deaerated n-hexane with 254 nm UV light afforded a novel rearranged photoproduct 4 (57% yield) along with some decomposition products of unknown structure as shown in Scheme 2, when 85% of 1 was photolyzed. The formation of a novel photoproduct 4 can best be explained in terms of the initial formation of silatriene intermediate 2 (path b) arising from 1,3-migration of trimethylsilyl radical, which is formed via the homolytic cleavage of silicon-silicon bond of pentamethyldisilanyl group in the photoexcited state of 1 to the C6 position of benzene ring.…”

Section: Methodsmentioning

confidence: 99%

Photoinduced Rearrangement Reaction of 2-(Pentamethyldisilanyloxymethyl) phenylpentamethyldisilane

Park¹,

Gong²

2010

Bulletin of the Korean Chemical Society

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“…15 Further examples have been identified as minor products from photolysis of phenyldisilane derivatives with alkynes 16 or alkenes. 17,18 Although providing useful mechanistic insight into certain pathways leading to formation of silepins, none of these routes are however of any significant preparative use due to low isolated yields of products originating from complex reaction mixtures. As already indicated above, simple silepins undergo thermolysis with extrusion of silylene species leading to benzenoid aromatics, 15,19 but other, more complex degradation pathways are also known for silepins bearing various silyl-containing substituents.…”

Section: Silepinsmentioning

confidence: 99%