The methyl α-diazophosphinates 5a–5f react with bromo trimethylsilane in benzene at room temperature to the silyl esters 6a–f which are transformed into the tert-butylammonium α- diazophosphinates 7a–7f with tert-butylamine/ether. An analogous reaction sequence succeeds with α-diazophosphonate derivatives (13a–13g→ 14a–14g→ 15a–15g). The same result is received by treatment of the starting compounds with an excess of tert- ...