Tris[2-(2-pyridyl)ethyl]phosphine chalcogenides,
prepared easily from 2-vinylpyridine and phosphorus red, react chemoselectively
with three equivalents of 4-toluenesulfonic or trifluoromethanesulfonic
acids under mild conditions (THF, r.t., 50-80 min, THF)
to give the corresponding tri(pyridinium) triflates and tosylates
in quantitative yields.
tris[2-(2-pyridyl)ethyl]phosphine oxide - tris[2-(2-pyridyl)ethyl]phosphine sulfide - tris[2-(2-pyridyl)ethyl]phosphine selenide - 4-toluenesulfonic acid - trifluoromethanesulfonic acid - quaternization reactions - tri(pyridinium) triflates
and tosylates
