Triphenylphosphine-sulfur trioxide

There are several methods reported in the literature for transforming vicinal diols into ct-diketones while avoiding the risk of C-C bond cleavage.26 Examples include the standard Swem conditions (dimethyl sulfoxide and oxalyl chloride followed by triethylamine), or the use of DMSO activated by acetic anhydride, pyridine-sulfur trioxide complex, or dicyclohexylcarbodiimide (Mq/J-att oxidation). Diones are also obtained by treatment with benzalacetone as a hydride acceptor in the presence of catalytic amounts of tris(triphenylphosphine)ruthenium dichlonde [(PPh RuCFl.27 Recent developments include the use of w-iodoxyben/.oic acid28 or the oxoammonium salt of 4-acctamidoletramethylpipcridine-1-oxyl and y -toluencNulfonic acid.29... [Pg.156]

More contributions of these reactions to the organophosphorus chemistry have been described. 14 and sulfur trioxide form azido-TMS-sulfate (481) which, if treated with triphenylphosphine and after subsequent hydrolysis of 482, gives rise to triphenyl-phosphoranimino-sulfonic acid (483)245 ... [Pg.73]

Potassium permanganate. Dimethyl sulfide-Chlorine. Dimethyl sulfoxide. Dimethyl sulfoxide-Chlorine. Dimethylsulf-oxide Sulfur trioxide. Dipyridine chro-mium(VI) oxide. Iodine. Iodine-Potassium iodide. Iodine tris(trifluoroacetate). Iodosobenzene diacetate. Isoamyl nitrite. Lead tetraacetate. Manganese dioxide. Mercuric acetate. Mercuric oxide. Osmium tetroxide—Potassium chlorate. Ozone. Periodic acid. Pertrifluoroacetic acid. Potassium ferrate. Potassium ferricyanide. Potassium nitrosodisulfonate. Ruthenium tetroxide. Selenium dioxide. Silver carbonate. Silver carbonate-Celite. Silver nitrate. Silver oxide. Silver(II) oxide. Sodium hypochlorite. Sulfur trioxide. Thalli-um(III) nitrate. Thallium sulfate. Thalli-um(III) trifluoroacetate. Triphenyl phosphite ozonide. Triphenylphosphine dibromide. Trityl fluoroborate. [Pg.297]

Sulfur trioxide is a strong Lewis acid and reacts with Lewis bases (indicated below as L) such as pyridine and triphenylphosphine to give stable adducts ... [Pg.215]

Triphenylphosphine 493 reacts with chlorosulfonic acid to form the triphenylphos-phine-sulfur trioxide adduct 494 (Equation 157). In this reaction, the triarylphosphine reacts in an analogous manner to a tertiary amine which with chlorosulfonic acid yields the corresponding amine-sulfur trioxide complex (see Section 9, p 101). The adduct 494 was stable in air and was useful as a coupling reagent in peptide synthesis." ... [Pg.128]