Photolysis and thermolysis of azophosphonate model compounds in solid matrices investigated by UV–Visible and infrared spectroscopy

Diazonium Salts as Nitrogen-Based Lewis Acids

“…27 A few decades later in 1997, Wokaun and co-workers reacted tris(dimethylamino)phosphine with equimolar amounts of various diazonium tetrafluoroborate salts in acetonitrile (R = Cl, CN, SO NH 2 , C(O)OEt; Figure 2) affording the corresponding azophosphonium tetrafluoroborates 12 [p-R-PhN 2 (P(NMe 2 ) 3 )][BF 4 ] in good yields (80-95%), which can be handled in air. 29 In 1999, Flower and co-workers obtained the azophosphonium salt 13 (R = 6-naphthalen-2-ol; Figure 2) in anhydrous THF, which they only characterized spectroscopically by 31 P NMR spectroscopy ( 31 P{ 1 H} NMR:  = 40 ppm). 30 Furthermore, Matsuda and co-workers obtained [(p-R-C 6 H 4 )N 2 (PR 3 )][BF 4 ] (R = H, CH 3 , MeO, F) upon reaction of the corresponding diazonium salt with (PPh 3 ) 4 Pd; they reported it as a side-product in their reaction.…”

“…For reaction with the phosphite (EtO) 3 P additionally a coupled product (29) of the aryl radical with the phosphine radical cation was observed. This was described as being formed by analogy with the Arbuzov reaction (Scheme 17).…”