Reaction of N-(trifluoromethanesulfonyl)trichlorophosphazene with alcohols

Trifluoromethanesulfonamides and Related Compounds

“…The ease of isomerization is a function of electronegativity of substituent R: for R = CH 3 the rearrangement proceeds much easier than for R = CH 2 C 2 F 4 H, as should be expected for migration of an electropositive group to the nitrogen atom. The comparison with the literature data allowed the authors to conclude that the migration of the methyl group from oxygen to nitrogen is easier the higher the electronegativity of substituent X in XSO 2 is; for X = Ar the rearrangement occurs only at 200 °C, for X = CF 3 it takes several days at room temperature, and for the most electronegative X = F, Cl, it is completed in 20 min at 35–40 °C …”

“…However, our monitoring of the reaction of CF 3 SO 2 NPCl 3 with methanol and trifluoropropanol has shown that the reaction is not as simple as that. First, N -(triflyl)(alkoxydichloro)phosphazenes are formed, which rearrange upon standing into dichlorides of N -alkyl- N -(triflyl)amidophosphoric acids …”

“…It is worth mentioning that the action of strong acids is principally different from that of weak OH acids, like alcohols or phenols, which give the products of partial or complete chlorine substitution (see, e.g., refs and ). In other words, with strong acids, “N-protonation” takes place, whereas with weak acids, due to weak basicity of the nitrogen atom in phosphazenes, the “P-oxygenation” predominates.…”

N-Triflylphosphoramides: highly acidic catalysts for asymmetric transformations

“…This method (Scheme 4b), developed by the group of List, [69][70][71] uses N-triflyl phosphorimidoyl trichloride (Cl 3 PvNTf ) as a phosphorylating reagent-this compound can be synthesised on a relatively large scale from phosphorus(V) pentachloride and TfNH 2 at 110 °C without the need of a solvent followed by fractional distillation. 69,72,73 Such a method furnishes intermediate 1.20, which by subsequent hydrolysis affords the desired catalyst. The shorter reaction times, room temperature and high yields make this procedure an appealing alternative.…”