Triphenylphosphine ditriflate

Sulfonamides may be directly synthesized from sulfonic acid salts by treatment with triphenylphosphine ditriflate followed by an amine <2004JA1024>. This procedure, that avoids the generation of sulfonic acids, converts sulfonic acid salt 129 to sulfonamide 130 in 81% yield (Equation 92). Problems associated with the removal of triphenylphosphine oxide by-products can be alleviated by performing the reaction with polystyrene-supported phosphine. 

Sulfonamides can be directly synthesized from sulfonic acid salts by treatment with triphenylphosphine ditriflate followed by an amine <2004JA1024>. 

Polymer-supported triphenylphosphine ditriflate (37) has been prepared by treatment of polymer bound (polystyrene-2% divinylbenzene copolymer resin) triphenylphosphine oxide (36) with triflic anhydride in dichloromethane, the structure being confirmed by gel-phase 31P NMR [54, 55] (Scheme 7.12). This reagent is effective in various dehydration reactions such as ester (from primary and secondary alcohols) and amide formation in the presence of diisopropylethylamine as base, the polymer-supported triphenylphosphine oxide being recovered after the coupling reaction and reused. Interestingly, with amide formation, the reactive acyloxyphosphonium salt was preformed by addition of the carboxylic acid to 37 prior to addition of the corresponding amine. This order of addition ensured that the amine did not react competitively with 37 to form the unreactive polymer-sup-ported aminophosphonium triflate. 

Scheme 7.12 Preparation of polymer-supported triphenylphosphine ditriflate (37).

DEHYDRATION Diethoxyaluminum chloride. Lithium n-propylmercaptide. N-Methyl-N,N -di-r-butylcarbodiimidium tetrafluoroborate. o-Nitrobenzenesulfonyl chloride. Potassium acetate. Thiobenzoyl chloride. Triphenylphosphine ditriflate. Triphenyl-phosphine methiodide. 

AMIDES Boron tribromide. Boron trifluoride etherate. 6-Chloro-l-p-chlorobenzene-sulfonyloxybenzotriazole. Diethylphosphoryl cyanide. Dihalobis(triphenylphosphine)-palladium(H). Dihalobis(triphenylphosphine)paUadium(ll) complexes. Palla-dium(II) chloride. Sodium amide. Trimethylsilyl isocyanate. Triphenylphosphine ditriflate. 

T riphenylphosphine—Diethyl azodi-carboxylate, 280, 645 Triphenylphosphine dibiomide, 645-646 Triphenylphosphine dichloride, 646-647 Triphenylphosphine dihaiides, 647-648 Triphenylphosphine diiodide, 648 Triphenylphosphine ditriflate, 648 Triphenylphosphite methiodide, 649 Triphenyl phosphite ozonide, 435 Triphenyl(prop-2-ynyl)phosphonium bromide, 494 Triphenylsilanol, 655, 656 Triphenylstannane, 649 Triphenyltin hydride, 649 Triphenylvinylsilane, 637 Triphosphopyridine nucleotide, 36-37 Tri- -propyl orthovanadate, 655 Tris-annelation, 410 Ttis(aquo)hexa-fi-acetato-p,-oxotri-ruthenium acetate, 425-426,650 Tris(dimethoxyboryl)methane, 328, 329 Tris(dimethylamino)borane, 554 Trishomocubanone, 108 Tris(neomenthyldiphenylphosphine)-chlororhodium, 416... 

The reaction of Tf20 with PhsPO in CH2CI2 at 0°C affords triphenylphosphine ditriflate, which can be used as an oxygen activator, and then to a diphosphonium salt (eq 35). ... 

The polymer bound triphenylphosphine oxide, lb, is readily converted to the ditriflate, 2b, following Hendrickson and Schwartzman s procedure for the synthesis of triflyltriphenyl-phosphonium triflate, 2a, (8). Much of our work has been the exploration of the monomeric system, first the conversion of the alcohol to ROP(Ph)3+OTf- and the subsequent reactions of these with various nucleophiles. 

Reactions of the bound alkoxyphosphoniura triflate (formed in an identical manner to that of the unbound analog 3a), with the nucleophiles shown in Table II were followed by ir and the yields determined by gc. Our few preliminary results demonstrate that their alkylating abilities are comparable to that of the unanchored alkoxyphosphoniums. The triphenylphosphine oxide polymer produced can be recycled back to the ditriflate, with triflic anhydride. 

The treatment of [bis(phenyliodonium)]ethyne ditriflate with triphenylphosphine has also been investigated40,41. The products depend on the stoichiometric ratios of the reactants. Thus, with one equivalent of triphenylphosphine, a monoiodonium-monophos-phonium derivative of acetylene is obtained, but with two equivalents of the phosphine, [bis(triphenylphosphonium)]ethyne ditriflate is produced (equation 72). When three equivalents of triphenylphosphine are employed in acetonitrile spiked with H20 or D20, a fram -alkenediyl bisphosphonium salt is generated (equation 73)41. The reduction of the triple bond and formation of triphenylphosphine oxide in this reaction is thought to proceed at the bisphosphonium alkyne stage41. 

Oxybis(triphenylbismuth) diperchlorate-bis(triphenylphosphine oxide) 281 Oxybis(triphenylbismuth) ditriflate 280... 

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