Synthesis of Tetraphenylstannacyclopentadienes (Stannoles). II. Derivatives and Adducts of 1,1-Dihalo-2,3,4,5-tetraphenylstannoles.
OKLAHOMA UNIV NORMAN DEPT OF CHEMISTRY
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1,1-Dibromo- and 1,1-diiodo-2,3,4,5-tetraphenyl-1-stannacyclopentadiene, dihalotetraphenylstannoles, XYSnC4C6H54, can be derivatized to form a series of disubstituted products in which X Y N3, iso-NCO, iso-SCN, OCOCH3, SCSNC2H52, NCH32 and PC6H52. Fluorination by KF in acetone results in the X F, Y Br or Y I product only, and lithioamination by LiNSiCH332 yields the X NSiCH332, Y Br product only. Attempted synthesis of the dihalostannoles by halogenation of the intermediate tinII stannole from 1,4-dilithio-1,2,3,4-tetraphenyl-1,3-butadiene and tinII chloride yields only the ring-opened products 4-bromo-1,2,3,4-tetraphenylbutadienyltin tribromide or 4-iodo-1,2,3,4-tetraphenylbutadienyltin triiodide. Even gentle chlorination of hexaphenylstannole by elemental chlorine cleaves the ring tin-carbon bonds to form cis-cis-1,4-dichloro-1,2,3,4-tetraphenylbutadiene-1,3 and diphenyltin dichloride, while the action of a glacial acetic acidacetic anhydride mixture yields tetraphenylfuran and diphenyltin diacetate.
- Organic Chemistry