(Trimethylsilyl)phosphine as a Versatile Reagent for Syntheses of New 4-Sila- and 4-Phosphaphosphorinanes.

(Trimethylsilyl)phosphine (Me(3)SiPH(2)) undergoes radical P-H bond addition to vinylphosphines and -silanes to form new 4-phospha- and 4-silaphosphorinanes [vinyl reagent]: [PhP(CH=CH(2))(2)], PhP(C(2)H(4))(2)PSiMe(3) diastereomers (9A/9B); [Et(2)NP(CH=CH(2))(2)], Et(2)NP(C(2)H(4))(2)PSiMe(3) (11); [Me(2)Si(CH=CH(2))(2)], Me(2)Si(C(2)H(4))(2)PSiMe(3) (14); [Si(CH=CH(2))(4)], (CH=CH(2))(2)Si(C(2)H(4))(2)PSiMe(3) (16) and [Me(3)SiP(C(2)H(4))(2)](2)Si (17). Reactions are accompanied by formation of only small quantities of the Markovnikov addition product phospholanes. Methanolysis of the new silylphosphines yields PhP(C(2)H(4))(2)PH diastereomers (10A/10B), Me(2)Si(C(2)H(4))PH (15), (CH=CH(2))(2)Si(C(2)H(4))(2)PH (18), and [HP(C(2)H(4))(2)](2)Si (19).