4- Phenyl trifluoroacetate, reaction with

A" 0-Butenolide, 46, 22 /-Butyl alcohol, in synthesis of phenyl /-butyl ether, 45, 89 reaction with sodium cyanate and trifluoroacetic acid, 48, 32 /-Butyl azidoacctatc, 46, 47 hydrogenation of, 45, 47 /-Butyl carbamate, 48,32 /-Butyl chloroacetate, reaction with sodium azide, 45, 47 /ra S-4-/-BuTYI,CYCLOHEXANOL, 47,16... 

Acylation The reagent catalyses the arylation of activated aromatic compounds by reaction with carboxylic acids. Thus methyl phenyl ether can be acylated with acetic acid in presence of trifluoroacetic anhydride in good yields. 

Kinetic studies of the reaction of Z-phenyl cyclopropanecarboxylates (1) with X-benzylamines (2) in acetonitrile at 55 °C have been carried out. The reaction proceeds by a stepwise mechanism in which the rate-determining step is the breakdown of the zwitterionic tetrahedral intermediate, T, with a hydrogen-bonded four-centre type transition state (3). The results of studies of the aminolysis reactions of ethyl Z-phenyl carbonates (4) with benzylamines (2) in acetonitrile at 25 °C were consistent with a four- (5) and a six-centred transition state (6) for the uncatalysed and catalysed path, respectively. The neutral hydrolysis of p-nitrophenyl trifluoroacetate in acetonitrile solvent has been studied by varying the molarities of water from 1.0 to 5.0 at 25 °C. The reaction was found to be third order in water. The kinetic solvent isotope effect was (A h2o/ D2o) = 2.90 0.12. Proton inventories at each molarity of water studied were consistent with an eight-membered cyclic transition state (7) model. 

For the three reactions represented in Fig. 12 the maximum rate of hydrolysis in acid represents only a mpdest acceleration, compared with the rate in initially neutral solution. Bunton and Hadwick89,90 explained the maximum for methyl and phenyl trifluoroacetate in terms of negative salt effects on both acid-catalyzed and neutral reactions. Consistent with this interpretation, it was demonstrated directly that the rate of neutral hydrolysis is decreased by added salts. The effect of added salt should be to decrease the activity of water, and perhaps also to salt in the ester. 

Etherification of isohexides with substituted-benzyl chloride in aqueous sodium hydroxide, or by means of sodium hydride in dimethyl sulfoxide, yields mixtures of mono- and bis-ethers, which can be conventionally separated by distillation or by column chromatography.176 The preparation of some phenyl ethers was also described, using the tosylate-phenoxide exchange reaction. Monoethers (88) synthesized in this way were transformed into carbamates (89) by reaction with sodium cyanide-trifluoroacetic acid (see Scheme 18). 

The effect of the nature of the electrophile on the stereoselectivity of reactions with substrates containing a terminal alkene and an allylic substituent is dramatically illustrated by some recent results with palladium electrophiles.124 Cyclizations of 3-methyl- or 3-phenyl-5-hydroxyalkenes with palladium catalysts proceed with high selectivity (>9 1) for the 2,3-trans isomer (equation 41).50-124 It is suggested that the steric interactions of the palladium-alkene complex affects the stereochemistry of these cyclizations. In some related cyclizations to form tetrahydropyran products (equation 42 and Table 10), reaction with iodine in the presence of sodium bicarbonate gives a different major diastereomer from cyclization with mercury(II) trifluoroacetate or palladium chloride.123... 

Carbaryl, propoxur (isopropyl phenyl N-metbyl carbamate) Crops Reaction with trifluoroacetic anhydride GC with ECD 0.005 ppm [66]... 

Alkenes formed bis trifluoroacetates of glycols in their reaction with BTI with phenylated alkenes rearranged products dominated, e.g. tetraphenylethylene was... 

The steric influence of the orr/io-substituent does not interfere strongly with the overall yield of the C-arylation 2,4-di-re/t-butylphenol (17) afforded the 6-phenyl derivative (18) in 65% yield by reaction with pentaphenylbismuth and in 81% yield with triphenylbismuth bis(trifluoroacetate) and BTMG (A -/ /t-butyl-iV " -tetramethylguanidine). 

The O-phenylation reaction with tetraphenylbismuthonium trifluoroacetate (6) was also extended to enols. A series of enolised dicarbonyl compounds were 0-phenylated in modest to moderate yields with this reagent under neutral or acidic conditions, the best yields being again obtained under acidic conditions. ... 

The important drop in the yields from primary to secondary alcohols was attributed in part to a competing trifluoroacetylation induced by the presence of phenyl trifluoroacetate, a decomposition product of the reagent (6). Reaction of 3p-cholestanol (77) with (6) led the 0-phenyl ether (78) in 29% yield, together with 3P-cholestanyl trifluoroacetate (79) in 65% yield. 

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