Boron trifluoride n-butyl etherate

CyclopropanecarboxaUehytte. Dehydration of a mixture of cis- and froni-cyclo-butane-l,2-diol (I) with boron trifluoride n-butyl etherate at 230° yields cyclopropane-carboxaldehyde (2) in 65-80% yield. Dehydration of (I) with p-toluenesulfonic acid gives (2) in somewhat lower yields (66%)- ... 

Boron trifluoride n-butyl etherate, BF3 0(CH2CH2CH2CH3)2. Mol. wt. 198.04. Supplier Fluka. 

Aluminum phosphide Amyl trichlorosilane Benzoyl chloride Boron tribromide Boron trifluoride Boron trifluoride etherate Bromine pentafluoride Bromine trifluoride n-Butyl isocyanate Butyllithium Butyric anhydride Calcium Calcium carbide Chlorine trifluoride Chloro silanes Chlorosulfonic acid Chromium oxychloride Cyanamide Decaborane Diborane... 

Preparation of Poly(vinyl n-butyl ether) Using Boron Trifluoride Etherate... 

Under the catalysis of mercuric oxide and boron trifluoride-diethyl ether, the reaction of methanol with 1,2-hexadiene afforded 2,2-dimethoxyhexane [6]. Hydration with sulfuric acid led to methyl n-butyl ketone [6],... 

Commercial polymers have been produced from methyl, ethyl, isopropyl, n-butyl, isotubtyl, t-butyl, stcaryl, benzyl and trimethylsilyl vinyl ethers. The polylmethyl vinyl ether) called PVM or Resyn is produced by the polymerization of the monomer by boron trifluoride in propane at —40°C in the presence of traces of an alkyl phenyl sulfide. The polymer may have isotactic, syndiotactic or stereoblock configurations depending on the solvent and catalyst used. 

O-tert-Butyl trichloroacetimidate, prepared in 70% yield by reacting potassium rerr-butoxide with trichloroacetonitrile, reacts with carboxylic acids and alcohols in the presence of a catalytic amount of boron trifluoride etherate at room temperature in cyclohexane-dichloromethane [Scheme 6.35], 7 The method also converts alcohols to ferr-butyl ethers (see section 4.3.2). A very similar reaction that allows /erf-butylation under essentially neutral conditions on a large scale involves reaction of a carboxylic acid with 3-4 equivalents of JV,N -di-isopropyl-Orerf-butylisourea88 [Scheme 6,36].56S9 The reaction proceeds via a tertiary carbocation ion intermediate and since capture of the cation is inefficient, excess isourea is required. The presence of alcohols is tolerated but not thiols or unhindered amines. The reaction conditions are compatible with a range of acid sensitive groups such as AMrityl derivatives and cydopentylidene acetals.90... 

Analogous to epoxides, aziridines can be prepared by the methylenation of imines. In this case, ethyl diazoacetate is the most common source of carbenes. For example, the imine derived from p-chlorobenzaldehyde 148 is converted to the c/j-aziridinyl ester 149 upon treatment with ethyl diazoacetate in the presence of lithium perchlorate <03TL5275>. These conditions have also been applied to a reaction medium of the ionic liquid l-n-butyl-3-methylimidazolium hexafluorophosphate (bmimPFe) with excellent results <03TL2409>. An interesting enantioselective twist to this protocol has been reported, in which a diazoacetate derived from (TJ)-pantolactone 150 is used. This system was applied to the aziridination of trifluoromethyl-substituted aldimines, which were prepared in situ from the corresponding aminals under the catalysis of boron trifluoride etherate <03TL4011>. 

AMINO GROUP Boron trifluoride ether-ale. l-r-Bulyloxycarbonyltriazole-1,2,4, Di-t-butyl dicarbonate. 4-Dimethylamino-1-t-butyloxycarbonyl pyridinium chloride. CARBONYL GROUP Ceric ammonium nitrate. 1,2-Dihydroxy-3-bromopropane. Sodium N-chloro-p-toluenesulfonamide. Thallium(lll) nitrate. Trichloroethanol. Trimcthylsilyl cyanide. Chloromethyl methyl sulfide. N,N -Diisopropylhydra-zinc. Trichloroethanol. 

N-Alkylation of anthranils has been achieved using r-butyl alcohol in 60% perchloric acid,233,234 methyl fluorosulfonate,235 dimethyl sulfate,236 triethyloxonium tetrafluoroborate,237 and, unusually, trialkyl orthoformates in the presence of boron trifluoride etherate.237 Rate studies for the N-methylation of anthranils in dimethyl sulfate are available.36... 

Preparation.—Synthesis of acid-labile esters can be achieved by treatment of the corresponding lithium alkoxide, from the alcohol and n-butyl-lithium, with an acid chloride t-butyl pivalate can be obtained in 64% yield by this procedure. Hindered acids are esterified by triethyloxonium fluoroborate in the presence of ethyl di-isopropylamine. The use of boron trifluoride etherate-alcohol is recommended as a mild, efficient esterification method, as is the employment of alkyl t-butyl ethers, which react with carboxylic acids under acid catalysis to give the alkyl ester, isobutene, and water, no free alcohol being ever present. 

Lithium tetrafluoroborate in wet acetonitrile has been described as an effective combination for the hydrolysis of acetals under mild weakly acidic conditions. Dithians were unaffected. Methods for the hydrolysis of thioacetals continue to appear. Reagents that have been described include a polystyryl-mercury(n) trifluoroacetate combination, which retains the metal on the resin, lead(iv) dioxide and boron trifluoride etherate, aqueous hydrochloric acid in dioxan containing dimethyl sulphoxide, methyl-bis(methylthio)sulphonium hexa-chloroantimonate, and iodoxybenzene, catalysed by toluene-p-sulphonic acid. Dithioacetals derived from ethane-1,2-dithiol may be cleaved with dimethyl sulphoxide in combination with either t-butyl or trimethylsilyl bromides and iodides. Regeneration of ketones from ethanediyl-S S -acetals via the lithium-di-isopropylamide-promoted fragmentation to the thioketone and subsequent hydrolytic work-up only gives satisfactory yields for aryl methylketone derivatives. Dithioacetal SS-dioxides are rapidly cleaved in hot methanolic hydrochloric acid solution. ... 

In this regard, zirconium-butene complex ( Cp2Zr ) [74] was widely used to promote the carbocyclization of vinyl glycosides [75], Thus, sequential treatment of 5-vinyl pyranose 91 with Cp2Zr-(n-Bu)2 (prepared in situ fromzirconocene dichloride and 2 equivalents of butyl lithium) and boron trifluoride etherate in THF afforded vinyl cyclopentanol 92 as the major product in a 75% yield (Scheme 3.36) [76]. 

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