Synthesis and reactivity of novel bis(stannyl)silanes

Bis(stannyl)silanes of types R3Sn-SiR'(2)-SnR3 and R-2(H)Sn-SiR'(2)-Sn(H)R- 2 with R' being methyl, phenyl, iso-propyl or tert-butyl have been synthesi zed by treatment of difunctionalized diorganosilanes with alkali stannides (R = Me, Bu-t; R' = Me,Pr-t; 1 - 6, 8) or with triphenyltin chloride and ma gnesium (R = Ph; R' = Me, Ph, Pr-i; 7, 9). Me3Sn-(SiBu2)-Bu-t-SnMe3 4, was halogenated using SnCl4, to yield the bis(chlorostannyl)silane 11. The reaction of bis(stannyl)diorganosilanes R3SnSiR'2SnR3 with catalytic am ounts of Pd(PPh3)(4) resulted in unexpected rearrangements under formation of the silyldistannanes R3SnSnR2SiR'R-2,. These compounds undergo addition reactions with alkynes. All compounds have been identified by NMR, IR, MS a nd elemental analysis. Compounds 5, 6 and 7 have also been characterized by X-ray crystallography.