The direct addition of P (O)–H bonds (dialkyl phosphites and diphenyl phosphonite) across various activated alkenes was catalyzed effectively by 1, 5, 7-triazabicyclo [4.4. 0] dec-5-ene (TBD). This is a mild, rapid and efficient protocol to generate P–C bonds. This simple procedure allows a series of dialkyl alkylphosphonates and trisubstituted phosphine oxides to be prepared in high yields. Further investigation resulted in a convenient one-pot, three- ...