Reactions of stabilised phosphorus ylide with nitrilium trifluoromethanesulphonate salts

Abstract

N-Methylnitrilium trifluoromethanesulphonates react readily with methoxycarbonylmethylene(triphenyl)phosphorane to give methoxycarbonylmethyl(triphenyl)phosphonium trifluoromethanesulphonate and the new phosphonium trifluoromethanesulphonates [Ph₃PC(CO₂Me)CRNHMe]⁺OTf^–(R = Prⁱ, Ph, 2-MeC₆H₄, 4-MeC₆H₄, Me) in moderate yields. ³¹P and ¹³C NMR spectroscopic data indicate a significant contribution from the resonance form [Ph₃PC(CO₂Me)–CRNHMe]⁺OTf^– in the compounds.