Silane bromo

Gas chromatographic analysis at 79° using a flame detector in conjunction with a 183 x 0.32 cm. stainless-steel column containing Dow-Corning 550 fluid on silanized support gave peaks for l-bromo-3-chloropropane (6.5 minutes) and 6-chloro-2-hexyne (9.3 minutes) whose areas were shown to be proportional to the mole fractions. The latter were determined by integration of the expanded (50 Hz sweep width)... 

To a stirred solution of 110 mg (0.246 mmol) of benzyl (3S,5S,6/f)-3-bromo-2-oxo-5,6-diplienyl-4-morplio-linecarboxylate in 2 mL of dry tilt is added 150 tL (0.944 mmol) of trimcthyl(2-propenyl)silane followed by addition of 2.5 mL of a 0.187 M solution of zinc chloride in THF (0.472 mmol). After stirring for 60 h at 25 "C the mixture is poured into water and thoroughly extracted with CH,CL. The combined extracts... 

Heteropolycyclic compounds were obtained [29] by treating bromo furylethers with tris-(trimethylsilyl)silane (TTMSS) in hot toluene containing a catalytic amount of AIBN (Equation 1.12). 

Allyl silanes react with epoxides, in the presence of Bp3-OEt2 to give 2-allyl alcohols. The reaction of a-bromo lactones and CH2=CHCH2Si SiMe3)3 and AIBN leads to the a-allyl lactone. " Benzyl silanes coupled with allyl silanes to give ArCH2—R derivatives in the presence of VO(OEt)Cl2 " and allyltin compounds couple with allyl silanes in the presence of SnCU. " Allyl silanes couple to the a-carbon of amines under photolysis conditions. ... 

Copper(l) chloride Copper chloride (8,9) (7758-89-6) tert-Butyl alcohol (8) 2-Propanol, 2-methyl- (9) (75-65-0) (3-Bromo-3,3-difluoropropyl)trimethylsilane Silane, (3-bromo-3,3-difluoropropyl)-trimethyl- (12) (134134-62-6)... 

Silane, (3, 5-dimethyl-2, 4, 6-trinitrophenyl) trimethyl-Benzene, 1, 3-Bis (1, l-dimethylethyl)-2-methoxy-5-nitro Benzene, 1-(1, l-dimethylethyl)-2-methoxy-3-nitro Benzene, 2-methoxy-4-methyl-l, 3,5-trinitro Benzaldehyde, 3-(l,l-dimethylethyl)-2-methoxy-5-nitro Benzene, 2-bromo-4- (l,l-dimethylethyl)-l,3, 5-trinitro Benzene, l-(l,l-dimethylethyl)-2, 4-dimethoxy-5, 6-dimethyl-... 

SYNTHESIS OF SYMMETRICAL trans-STILBENES BY A DOUBLE HECK REACTION OF (ARYLAZO)AMINES WITH VINYLTRIETHOXYSILANE trans-4,4 -DIBROMOSTILBENE Benzene, 1,1 -(1,2-ethenediyl)bis[4-bromo-, (E)- using Silane, ethenyltriethoxy- ... 

Silane l(4-Bromo-phenoxy)-methyl]-difluoro-mcthyl- ElOa, 602 (20R -> 2 F)... 

The chlorination of 18b with PCI5 results in skeletal rearrangement to give three streoisomers of 4,8-dichlorooctakis(l,l,2-trimethylpropyl)tetracyclo[3.3.0.02,7.03 6]octa-silanes (25) (equation 8)54. Three stereoisomers (endo-exo, exo-exo, endo-endo) were isolated in a pure form and characterized by X-ray diffractions. The mechanism by which 25 is formed is not clear, but the first step involves the electrophilic attack by PCI5 on the strained Si—Si bond, followed by an intramolecular skeletal rearrangement. Bromo and iodo derivatives of 25 are also formed by the reactions of 18b with Br2 and with I255. 

Silica gel, 2 95 (correction), 5 55 platinized, use in preparation of hydrogen bromide, 1 152 Silicobromoform (see Silane, tri-bromo-)... 

Examples of halide reduction chemistry include the BU3 SnH-mediated reduction of iodide (41) en route to clavepictine A and B reported by Momose and coworkers64 (equation 17) as well as the reduction of iodide (42) during Danishefsky s work towards the synthesis of epothilone A (equation 18)73. Herzog and Roewer demonstrated that trimethyltin hydride can be used to effect the reduction of halooligosilanes to the corresponding silane in the presence of a Lewis base such as triphenylphosphine (equation 19)77, while Crich and Mo reported the beneficial effect of catalytic benzeneselenol during the BU3 SnH-mediated reduction and fragmentation of bromo-/) -lactones (43) (equation 20)94. 

Bromo- and even more iodo-substituted silanes are by far more sensitive to moisture than chlorosilanes, especially polyhalogenated species. Elemental bromine or iodine, respectively, is formed in air after a short time. 

The stereochemical course of solvolysis of a diastereomeric /3-bromo-silane, which was found to be trans elimination, as well as the observation of 1,2-silyl group migration in a process of substitution at the 0 carbon 143) are evidence of anchimeric assistance of the silyl group in ionization of the bond to the /3 carbon. It was further noticed 144) that after quenching the solvolysis reaction of /3-bromo-/3-dideuterioethylsilane the substrate recovered is a mixture of a and /3 deuterated isomers [Eq. (33)]. These... 

This is the most common method for chloro-, bromo-, or iodosilanes.6 Often, auxilary bases such as triethylamine or pyridine are added. But when hydrazine is treated with fluorosilanes or silanes, no condensation is observed because of the reduced reactivity. Fluorosilanes only form adducts with hydrazines, so that the reaction is stopped at step (a). Because of the extremely strong Si—F bond energy, no cleavage of HF or N2H4-condensation is observed.3,6 In this case another preparation method must be chosen. 

The formation of the silylhydrazines depends on the reactivity and the bulkiness of the halosilanes. The condensation increases with increasing number of the hydrogen atoms. While iodosilane or bromo(methyl)-silane yield the tetrakis(silyl)hydrazines,912... 

The ether solution of the lithium compound was dropped into the bromo-silane (cooled by an ice/NaCl cooling mixture) after an excess of Li resulting from the preparation of the Li compound had been removed. The reaction occurs instantaneously. 

Palladium-catalyzed processes are perhaps the most important developments in heterocyclic chemistry since CHEC-II and certainly since the original GHEG. The intermediates are never isolated, but, nonetheless, are essential to the transformations. Oxidative insertions of palladium (or less often, nickel, or iron), especially into bromo- or iodoazines, or triflates (prepared from -ols or - or -ones), or alternatively, the use of pyridine boronic acids, boronates, stannanes, silanes, and organmetallic species such as Grignard and zinc derivatives, form the basis of these methodologies. 

Caution. Heat is liberated during the course of the reaction with bromo-silane, and it may be necessary to cool the bottom of the reactor to — 78°. The brown residue remaining in the bottom of the reactor after sublimation of the product is pyrophoric and should be destroyed by the slow addition of n-butanol to the reactor. 

A THF solution of TASF (1.0 M solution, 0.40 ml, 0.40 mmol) was added to trimethyl(phenylethynyl)silane (40 mg, 0.40 mmol) and ( -C3H5PdCl)2 (2.7 mg, 0.0075 mmol) dissolved in THF (0.3 ml) at 0 °C under an argon atmosphere. (E)-l-Bromo-2-phenylethene was injected to the resulting solution, and the mixture was stirred at r.t. After completion of the reaction, the bulk of the solvent was removed by passing through a silica gel column with pentane as an eluent. Evaporation of pentane under reduced pressure gave pure l,4-diphenyl-3-buten-l-yne (83% yield). 

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