ChemInform Abstract: Dichlorosilylene Transfer Reactions Using Me3GeSiCl3

Trichlorosilyl germanes Me3GeSiCl3 (1) and Me2Ge(SiCl3)(2) (2) can be considered as new sources for SiCl2/SiCl3 transfer reactions under mild, aprotic conditions. Transfer reactions with chloro-and diphosphanes (RR'PCl: R, R' = Pr-i 4a and R = Bu-t, R' = Pr-i 4b; (R2P)(2): R = Bu-t 5a, R = Pr-i 5b) and amine-catalyzed cross experiments with alkyl(chloro)germanes R4-nGeCln (R = Me, Et and n = 1, 2) lead by silylene/silyl transfer to trichlorosilyl phosphanes or germanes. Trapping experiments with P-phosphanylphosphaalkenes (Me3Si)(2)C=P-PRR' (R = Bu-t, R' = Pr-i 621 and R, R' = Pr-i 6b) lead in a very selective fashion to a complete P=C double-bond cleavage by unique double SiCl2 addition with formation of stable P-phosphanylphosphadisiletanes 7a and 7b. In the case of compound 6b, a new centrosymmetric diphosphene (8) containing two dichlorosilyl phosphane groups was also formed. The reaction of 1 with P-chlorophosphaalkene (Me3Si)(2)C=P-Cl (9) leads to formation of diphosphene 10, transient P-silylphosphaalkene 11 and intermediate alkylidenediphosphane 12, all known from the reaction of 9 with Si2Cl6. Besides these known products, a new species with a P-31 NMR pattern closely related to those of 7a and 7b was detected.