Tris silane preparation

The silane, prepared by reduction of tris(2-propylthio)silylenium perchlorate with diisobutylaluminium hydride at —78°C, is subsequently isolated by high-vacuum distillation from the mixture. Heating must be very mild to prevent explosion. 

Dining preparation of tris(ketoximino)silanes, two violent explosions attributed to acid-catalysed exothermic rearrangement/decomposition reactions occurred. Although these silane derivatives can be distilled under reduced pressure, the presence of acidic impurities (e.g. 2-butanone oxime hydrochloride, produced during silane preparation) drastically reduces thermal stability. Iron(III) chloride at 500 ppm caused degradation to occur at 150°, and at 2% concentration violent decomposition set in at 50°C. 

TABLE 1. Physical Properties of Poly(isobornyl methacrylate-co-isobornyl acrylate)-co-methacryloxypropyl-tris(trimethylsiloxy)silane Prepared According to Current Application... 

Finally, reaction of -butyl lithium with tris(tert-butylamino)silane prepared in high yield from trichlorosilane and excess tert-butylamine, gives the completely lithiated silazane 4. An X-ray structure determination shows the compound to be dimeric in the solid (Fig. 4). While six lithium and two silicon atoms build up the inner cube of a rhombic dodecahedron, six nitrogen atoms occupy the remaining vertices. Compounds with an analogous structure have been reported by several research groups [2, 7, 15]. 

To prepare multifunctionalized symmetric organosilicon compounds by the polyalkylation of benzene. (2-chloroethyi)trichlorosilane and (3-chloropropyl)tri-chlorosilane were reacted with benzene. Polyalkylations of benzene with (2-chloroethyl)silane and (3-chloropropyl)silane were carried out in the presence of aluminum chloride catalyst at a reaction temperature of 80 C. The reaction of benzene with excess (2-chloroethyI )trichlorosilanes afforded pcralkylated product, hexakis(2-(trichlorosilyl)ethyl)benzene in good yield (70%). ... 

Another anti-cancer agent in clinical use is podophyllotoxin (3-59) this has an aryl tetrahydronaphthalene lignan lactone skeleton, and demonstrates potent tubulin-binding, anti-mitotic properties (Scheme 3.16) [30]. The Sherburn group [31] prepared this molecule by a tris(trimethylsilyl)silane promoted conversion of thionocarbonate 3-55 into the lactone 3-58, which proceeded with a yield of 38 %. As intermediates, the radicals 3-56 and 3-57 can be assumed. 

A new effective metal-ffee radical approach by Murphy et al generates the free radical by treatment with tetrathiafulvalene (TTF).1491 As depicted in scheme 16 the aromatic amine 79 is transformed into the diazonium salt 81 which on treatment with TTF leads to the radical 82. The following stereoselective cyclization gives the hexahydrocarba-zole scaffold 80, a substructure of alkaloids like aspi-dospermidin, strychnin and vinblastin. Also the non-toxic tris(trimethylsilyl)silane was employed for domino reactions, eg. for the preparation of the alkaloid aspidospermidin. 

Preparation of APES (amino-propyl-tri-ethoxy-silane)-treated slides... 

Organosilylphosphines are conveniently prepared by cleavage of alkyldiaryl-phosphines with lithium in THF, followed by treatment with chlorotrimethyl-silane,15 and tris(trimethylsilyl)phosphine has been prepared from the reaction of chlorotrimethylsilane with a mixture of sodium and potassium phosphides.16... 

This methodology was applied to a two-step sequence for the preparation of enantio-merically enriched dihydrobenzo[h]furans (Scheme 10.11) [46]. Rhodium-catalyzed allylic etherification of (S)-47 (>99% ee), with the sodium anion of 2-iodo-6-methyl-phenol, furnished the corresponding aryl allyl ethers (S)-48/49 as a 28 1 mixture of regioisomers favoring (S)-48 (92% cee). Treatment of the aryl iodide (S)-48 with tris(trimethylsilyl)silane and triethylborane furnished the dihydrobenzo[h]furan derivatives 50a/50b as a 29 1 mixture of diastereomers [43]. 

PHOTO-INDUCED RING EXPANSION OF l-TRIISOPROPYLSILYLOXY-1-AZIDOCYCLOHEXANE PREPARATION OF e-CAPROLACTAM [2 Azepin-2-one, hexahydro- from Silane, [(1-azidocyclohexyl)oxy]tris(1-... 

Silanes with functional groups like amino, cyano, flonr, phenyl, etc. are available commercially. The introduction of other functional gronps in the bonded moiety can be accomplished in two ways The silane with the functional gronp is prepared in sitn. To prepare a silane with an amide group, tri-alkoxy-3-aminopropyl silane is reacted with an acid chloride (C8 or C18). The thns prepared amide... 

Polyurethane hydrogels derived from UV curable urethane prepolymer and hydrophilic monomers were prepared and their properties were evaluated. The urethane prepolymer used in this study contained well-defined hard segments centered with a polyether-based soft segment and end-capped with methacrylate groups. The hydrophilic monomers studied were 2-hydroxyethyl methacrylate (HEMA), N-vinyl pyrrolidone, and glycerol methacrylate. Methacryloxypropyl tris(trimethysiloxy) silane (TRIS) was also used in some cases to modify properties. All compositions were UV... 

Preparation of poly(isobornyl methacry late - - isobor ny 1 acrylate)-ft-methacryloxypropyl-tris(trimethylsiloxy)silane... 

Jeong et al. (2) prepared crosslinked copolymers consisting of methyl tri-methoxy silane and dipentaerythritol penta-/hexa-acrylate, which were effective as organic thin-film transistors and used in liquid-crystal display devices. 

Triphenylsilyl- 300 and 2- and 3 - trimethylsily benzo[6]thio-phene 391,392 have been prepared, and their rates of cleavage by acids and bases measured. The reaction between 2-benzo[6 thienyltrichloro-silane and jp-bromophenyl methyl sulfide in the presence of sodium gives 2-[tri( )-methylthiophenyl)silyl]benzo[6]thiophene.3fl ... 

Reduction The asymmetric reduction of a series of aryl alkyl ketones with quaternary ammonium fluorides and silanes was reported by Drew and Lawrence [55]. In these reactions, the best catalysts (e.g., 6f) were from the qui ni ne/quinidine series in fact, a fluoride salt prepared from cinchonine gave no induction. The use of trimethoxysilane resulted in faster rates but lower enantioselectivites when compared with tris(trimethoxy)silane. It is interesting that, with the... 

The most common and convenient methods for the preparation of a variety of Si- and C-substituted silatranes are the reactions of trifunctional silanes with tris(2-hydroxyalkyl)amines (equation 1). Halo, alkoxy, acyloxy and dialkylamino groups can... 

Diinetiiyl(2,4,<>-tri-f-biitylplienoxy.)dilorasi]ane (1). This silane is suggested as an alternative to the expensive t-butyldimethylchlorosilane. It is more easily prepared (equation I) and is comparable as a silylation reagent. The resulting silyl enol ethers... 

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