Tris silane with acid chloride

Ballestri, M., Chatgilialoglu, C., Card , N., Sommazzi, A. The reaction of tris(trimethylsilyl)silane with acid chlorides. Tetrahedron Lett. 1992, 33, 1787-1790. 

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... 

One general method for acyl silane synthesis particularly successful for a-cyclopropyl examples (and even an a-cyclobutyl example) involves treatment of acid chlorides with lithium tetrakis(trimethylsilyl) aluminum or lithium methyl tris(trimethylsilyl) aluminium and cuprous cyanide (vide supra, Section III.A.3)77. For example, cyclopropyl acyl silane (23) was obtained in 89% yield by this process. Improved procedures use lithium t-butyldimethylsilyl cuprate78 and a dimethylphenylsilyl zinc cuprate species79,80 as reagents. 

Triphenylsilyl ethers are typically prepared by the reaction of the alcohol with triphenylsilyl chloride (mp 92-94 °C) and imidazole in DMF at room temperature. The dehydrogenative silylation of alcohols can be accomplished with as little as 2 mol% of the commercial Lewis acid tris(pentaf1uorophenyl)borane and a silane such as triphenylsilane or triethylsilane [Scheme 4.98]. Primary, secondary, tertiary and phenolic hydroxyls participate whereas alkenes, alkynes, alkyl halides, nitro compounds, methyl and benzyl ethers, esters and lactones are inert under the conditions. The stability of ether functions depends on the substrate. Thus, tetrahydrofurans appear to be inert whereas epoxides undergo ring cleavage. 1,2- and 1,3-Diols can also be converted to their silylene counterparts as illustrated by the conversion 983 98.4. Hindered silanes such as tri-... 

An acid chloride functionalized liquid crystalline material was tried to bond to the silanol group in silica. The direct reaction does not seem to be successful also, a spacer with a substituted dichlorodimethyl silane is not successful. The reaction scheme is shown in Figure 16.8. However, a separation performance is observed rather by deposition than by bonding of the liquid crystals. The liquid crystalline materials used in this study was based on cholesteric moieties. It is suspected that the reaction failed because of the large size of the cholesteryl group. In another study, dimeth-ylchlorosilane was added to the allyl group of 4-methoxyphenyl-4-allyloxy benzoate. This intermediate could be bonded to silica. Several other routes to fix liquid crystalline moieties on silica have been reviewed. ... 

In common with the synthesis of trifluoroisopropenyl-boronic acid, trifluoro-isopropenylsilane can be also prepared in 80% yield by treatment of 2-BrTFP with 1.2 equivalents of magnesium in the presence of 2.0 equivalents of dimethylphenylsilyl chloride in THF at — 10°C to room temperature (Scheme 26.45). This reagent can employ as CF2=C -CH2 synthon, but there have been no reports on the transition metal-catalyzed cross-coupling reaction of tri-fluorinated silane with halides. 

Allyl silanes react with a wide variety of electrophiles, rather like the ones that react with silyl enol ethers, provided they are activated, usually by a Lewis acid. Titanium tetrachloride is widely used but other successful Lewis acids include boron trifluoride, aluminium chloride, and trim ethyls ilyl tri-flate. Electrophiles include the humble proton generated from acetic add. The regiocontrol is complete. No reaction is observed at the other end of the allylic system. All our examples are on the allyl silane we prepared earlier in the chapter. 

Methyl groups by reduction of aromatic carboxylic acids with trichbrosilane-tri-n-propylamine.2 In a hood well vented to permit open atmospheric transfer of trichloro-silane and to remove hydrogen chloride off gas produced, a 300-ml. three-necked. 

An apparatus has been developed392 for the analysis of a mixture containing tri-chlorosilane, methyldichlorosilane, silicon tetrachloride, trimethylchlorosilane, di-methyldichlorosilane and methyltrichlorosilane by gas-liquid chromatography on a column of nitrobenzene supported on Celite 545. The column is eluted with nitrogen and the emergent gas is absorbed in flowing 0.01 N potassium ohloride. Hydrolysis of the silanes yields hydrochloric acid which alters the electrical resistance of the potassium chloride solution and this permits quantitative analysis of the silane mixture. 

Alkylation of the Uthium salt of TMSCHN2 (TMSC(Li)N2) gives a -trimethylsLlyl diazoalkanes which are useful for the preparation of vinylsilanes and acylsilanes. Decomposition of a-tri-methylsilyl diazoalkanes in the presence of a catalytic amount of Copper(I) Chloride gives mainly ( )-vinylsilanes (eq 12), while replacement of CuCl with rhodium(II) pivalate affords (Z)-vinylsilanes as the major products (eq 12). Oxidation of a-trimethylsilyl diazoalkanes with m-Chloroperbenzoic Acid in a two-phase system of benzene and phosphate buffer (pH 7.6) affords acylsilanes (a-keto silanes) (eq 12). ... 

Homoallyl bromide 314, prepared from readily available non-racemic ester 313, was converted to the Grignard reagent, which reacted with non-racemic epoxide, derived from D-maUc acid, to afford the alcohol 305. Ozonolysis of the alkene gave a ketone, which was converted into enol tri-flate 316. Ni-catalyzed cross coupling with trimethylsilylmethyl magnesium chloride afforded the allyl silane, which was converted into the allyl stan-nane 317. The asymmetric allylation of 313 with 317 provided 304 with a ration of 8.5 1. Methyl etherification and oxidative cleavage of exo-methylene... 

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