Trifluoromethanesulfonic acid hydroxylation

Strong acids promote electrophilic hydroxylation of aromatics. Thus, sodium perborate - trifluoromethanesulfonic acid has been found to be a versatile reagent for the monohydroxylation of arenes to phenols [55b]. 

Benzyl 2.2,2-trichloroacetimidate (bp 106-114 00.07 kPa) alkylates alcohols in the presence of trifluoromethanesulfonic acid. Esters, imides, isopropylidene and benzylidene acetals are unaffected. This method allows the formation of benzyl ethers in molecules that are base-sensitive. In the example [Scheme 4.167],2 benzylation of the p-hydroxy ester 167.L1 under the usual basic conditions would lead to retro-aldol reactions and/or elimination. A synthesis of the cellular messenger L-a-phosphatidyl-D-/nyo-inositol 3,4-bisphosphate exemplifies the use of trityl cation-promoted benzylation of two adjacent hydroxyls [Scheme 4.168]. ... 

Electrophilic Hydroxylation of Aromatics with Urea-Hydrogen Peroxide/Trifluoromethanesulfonic Acid... 

A number of aromatic compounds, such as benzene, toluene, ethylbenzene, o-xylene, mesitylene, chlorobenzene and napthalene have been reacted with the UHP/triflic acid system. A typical procedure for the hydroxylation of aromatics with urea-hydrogen peroxide/ trifluoromethanesulfonic acid involved slowly adding urea-hydrogen peroxide over a period of 3-5 hours to a solution of large excess of aromatic and trifluoromethanesulfonic acid maintained at -10 °C and then allowed to react for... 

Two equivalents of 1,1-dimethyl cyanamide add to acetone in the presence of 2 equiv of trifluoromethanesulfonic acid to furnish the oxadiazine 58, shown in Scheme 35. The proposed mechanism involves initial addition of dimethyl cyanamide to acidified acetone followed by a 1,3-hydroxyl shift and subsequent attack by a second molecule of 1,1-dimethyl cyanamide at the tertiary carbocation. The ultimate cyclization affords the 1,3,5-oxadiazine 58. X-Ray analysis, discussed in Section 9.09.3.2 <1996CC1731>, confirmed the structure of the obtained product to be that of 58 and not the expected 59, as depicted in Scheme 35. 

Monosubstituted derivatives of tetrahydrofuran (THF) have been known to be difficult to polymerize due to thermodynamic reasons. Bednarek and Kubisa extended cationic multibranching polymerizations to the class of five-membered cyclic ethers containing hydroxyl groups as substituents. They polymerized 2-(hydroxymethyl)tetrahydroftiran, using a trifluoromethanesulfonic acid initiator. MALDI-TOF mass... 

Scheme 5.5 Comb-type poly(lactide) by graft polymerization of lactide onto a poly(glycolic acid-serine-r-lactide) copolymer. In the copolymerization of the 2,5-morpholinedione with lactide, the R-group is a benzyl-protected CH2OH group that is deprotected with trifluoromethanesulfonic acid and thianisole/trifluoroacetic acid to give the hydroxyl functionalized macroinitiator.

NITRILES Acrylonitrile. N-Amino-4,6-diphenylpyridone. n-Hexylamine. Hydroxyl-amine hydrochloride. lithium diethylamide-Hexamethylphosphoric triamide. Methyl carbazate. Phenyl isocyanate. p-Toluenesulfonic acid. Trifluoromethanesulfonic an-... 

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