Diphenyldisilane

Irradiation (A, > 280 nm) of a hexane/isopropyl alcohol solution of the disilene precursor ( )-14 (Scheme 8) in a quartz tube at room temperature produced threo-1-isopropoxy-1,2-dimethyl-1,2-diphenyldisilane 37a, which is the product of syn addition of isopropyl alcohol to ( )-16 together with a small amount of the erythro-isomer 38a (37a/38a => 99/1, 62% yield). High syw-addition diastereoselectivity was also found... 

Results of the photolysis of both a meso and a racemic diastereomer of the 1,2-diphenyldisilane 392 indicated that the reaction leading to the silene 393, followed by its ene reaction with an alkene leading to the adduct 394, was a diastereospecific process206. A concerted mechanism, illustrated in equation 49 for one isomer of the disilane, was proposed to account for the results such results would not be expected of a process involving silyl radical intermediates, which had been proposed earlier as intermediates in the photolysis of disilanes. 

Disilametallacyclopentanes, 32a and 32b, can be prepared from mes< -l,2-di-f-butyl-l,2-diphenyldisilane-1,2-dithiol (31) in high yield (equations 13 and 14)4,5. Disilatitanacycle 32a can be isolated as green crystals in 80% yield, and zirconacycle 32b as a yellow crystalline solid in 90% yield. Disilatitanacycle 32a is relatively stable toward moisture and air, but zirconacycle 32b is unstable toward moisture and is air-sensitive. 

A different approach that even obviates the use of a preformed silyllithium reagent takes advantage of the cleavage of the Si-Si bond of a disilane by a copper salt. Hosomi and co-workers185 have reported on the reaction of various enones or enals 250 with hexamethyldisilane or l,l,2,2-tetramethyl-l,2-diphenyldisilane, catalyzed by copper(i) triflate-benzene complex (Scheme 61). The transformation requires heating to 80-100 °C in DMF or DMI and the presence of tri-/z-butylphosphine in order to stabilize the copper catalyst under these harsh conditions. The addition products 251 were obtained with high yield after acidic work-up. The application of the method to alkylidene malonates as the Michael acceptor was recently disclosed.1... 

Cyclic trisilane 323 upon steady-state photolysis (245 nm) was used for preparation of diphenylsilylene 324, the silicon analogue of singlet diphenylcarbene <2006JA14442>. Diphenylsilylene 324 was trapped by MeOH or triethylsilane to give diphenylmethoxysilane 325 and l,l,l-triethyl-2,2-diphenyldisilane 326 in 72 and 69% yield, respectively. 

Isomerization of alkenes is catalyzed by bis(j7 -allyl)(jj -cyclopentadienyl)vanadium(IV). Cyclohexene nndergoes catalytic stereoselective aerobic oxidation with CpV(CO)4. Reductive coupling (see Reductive Coupling) of aldehydes and aldimines is catalyzed by a Cp-substituted vanadium compound in the presence of a chlorosilane and zinc or aluminum. Vanadocene or bis( ] -cyclopentadienyl)dimethylvanadium(IV) catalyzes the synthesis of 1,2-diphenyldisilane and 1,2,3-triphenyltrisilane from phenylsilane. ... 

The sensitivity of Si-N bonds towards acidic conditions subsequently can be utilized to remove the amino groups and to restore the original Si-Cl functionalities, which provides an easy access to partially hydrogenated chlorodisilanes, which otherwise are rather troublesome to obtain. The attempted synthesis of 1,2-dihalodisilanes X-(SiH2)2-X with X = Cl or Br from 1,2-diphenyldisilane and HX, for instance, usually affords azeotropic mixtures of the corresponding dihalodisilane and benzene, which cannot be separated by distillation [3, 4], We found, that 6 and 8 are converted to 1,2-dichlorodisilane (9) and l-f-butyl-2-chlorodisilane (10), respectively, simply by treatment with dry HCl gas in pentane for 30 minutes at 0°C (Scheme 4). 

Reaction of bis(disilanyl)dithiane 6 with an equimolar amount of Pd(CN-t-Bu)2 in benzene was examined at room temperature. The reaction was completed within 5 min, affording l,l,2,2-tetramethyl-l,2-diphenyldisilane and a four-membered cyclic bis-(organosilyl) complex 7 in 85% yield after isolation by crystallization with pentane (Scheme 5). A crystal structure of 7 exhibited a distorted square planar structure, in which the two silicon atoms in the ring are separated only by 2.61 A. Presumably, the formation of 7 may have arisen from the simultaneous activation of the two Si—Si bonds on palladium, which led to intramolecular metathesis (disproportionation). 

Synthesis of Cyclotetrasilane-Fused Octasilacuneane 487 Wurtz-type coupling of 1,1-di-tert-butyl-1,2-dichloro-2,2-diphenyldisilane with lithium 487... 

Synthesis of Cyclopentasilane-Fused Hexasilabenzvalene 490 Wurtz-type coupling of 2,2-di-tert-butyl-1-chloro-1,1-diphenyldisilane with... 

Chloro(diethylamino)diphenylsilane (73.8 g, 255 mmol) was added dropwise to a mixture of lithium (4.25 g, 612 mmol) in THF (160 mL) at 0°C for 20 min. The mixture was stirred at 0°C for 7 h. The resulting silyllithium reagent was added dropwise to a solution of di-tert-butylchlorosilane (42.4 g, 237 mmol) in THF (150 mL) at 0°C for 45 min. The reaction mixture was stirred at room temperature for 15 h. A large amount of hexane was added to the reaction mixture. Insoluble materials were filtered off, and the filtrate was evaporated. The residue was distilled under reduced pressure with a Kugelrohr distillation apparatus (170°C/0.2 mmHg) to give 2,2-di-tert-butyl-l-diethylamino-1,1-diphenyldisilane (78.8 g, 84%) as a colorless liquid. 

Di-terf-hutyl- 1-chloro-1,1-diphenyldisilane, henzoyl peroxide, carhon tetrachloride. 

A solution of 2,2-di-terf-hutyl-l-chloro-l,l-diphenyldisilane (72.8 g, 202 mmol) and henzoyl peroxide (0.136 g, 0.561 mmol) in carhon tetrachloride (500 mL) was heated at 70°C for 1 day. Benzoyl peroxide (0.103 g, 0.425 mmol) was added again to the reaction mixture, and the solution was heated at 70°C for 2 days. The solvent was removed under reduced pressure. The residue was distilled under reduced pressure with a Kugelrohr distillation... 

A mixture of l,l-di-terf-butyl-l,2-dichloro-2,2-diphenyldisilane (20.0 g, 50.6 mmol) and lithium (0.735 g, 106 mmol) in THF (400 mL) was stirred at room temperature for 11 days. Ethanol (ca. 1 mL) was added to the reaction mixture, and the solvent was removed under reduced pressure. The residue was dissolved in chloroform and passed through a short column of silica gel. The filtrate was evaporated, and the residue was suspended in hot ethanol. After cooling, the suspension was filtered. The obtained solid was dried under reduced pressure to give... 

Di- ter -butyl-1 -chloro-1,1 -diphenyldisilane, lithium THF, chloroform, brine, anhydrous magnesium sulfate. 

A mixture of 2,2-di-terf-butyl-l-chloro-l,l-diphenyldisilane (23.5 g, 65.1 mmol) and lithium stick (0.515 g, 74.2 mmol) in THF (130 mL) was stirred overnight at room temperature. The solvent was removed under reduced pressure, and chloroform and water were added to the residue. The organic layer was separated, and the aqueous layer was extracted with chloroform. The combined organic layer was washed with water and brine, dried over anhydrous magnesium sulfate, and evaporated to give l,l,4,4-tetra-tert-butyl-2,2,3,3-tetraphenyltetrasilane (19.4 g, 92%) as colorless crystals. 

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