ORGN 466 |
| After the preparation of the silene >Si=C< and disilene >Si=Si<, many stable unsaturated silicon compounds have been synthesized to date. However, there were few known unsymmetrical R2Si=SiR'2 or heteronuclear R2Si=E'R2 (E' = heavier group 14 elements). We have developed a straightforward method for the synthesis of dimetallenes of the type >Si=E< by a coupling reaction of bis(di-tert-butylmethylsilyl)dilithiosilane (1) with 1,1-dihalosilanes, -germanes and -stannanes, which provides disilenes (2a), germasilenes (2b) and silastannenes (2c), respectively. The coupling of 1,1-dilithiosilane with tetrahalodisilanes (RSiX2X2SiR) gave the three-membered cyclotrisilene or tetrasila-1,3-butadiene derivative. A stable compound with a silicon-silicon triple bond, 1,1,4,4-tetrakis[bis(trimethylsilyl)methyl]-1,4-diisopropyl-2-tetrasilyne (3), was also recently synthesized by the debromination of corresponding precursor. Despite the steric protection, the Si-Si triple bond in 3 does undergo addition reactions with halogen, cis-butene, and trans-butene. The detailed reactivity of the disilyne 3 will be discussed. The chemistry of silyl radicals, silyl cations, and triplet silylene will be also presented. |
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Frederic Stanley Kipping Award in Silicon Chemistry
1:00 PM-5:00 PM, Wednesday, 29 March 2006 Georgia World Congress Center -- Georgia Ballroom 2, Oral
Division of Organic Chemistry |