- Structure and chemistry of 1-silafluorenyl dianion, its derivatives, and an organosilicon diradical dianion
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1-Silafluorene dianion was synthesized by potassium reduction of 1,1-dichloro-1-silafluorene in refluxing THF. The X-ray structure of 1,1-dipotassio-1-silafluorene (3b) shows C-C bond length equalization in the five-membered silole ring and C-C bond length alternation in the six-membered benzene rings, indicating aromatic delocalization of electrons in the silole ring. The downfield 29Si chemical shift at 29.0 ppm and theoretical calculations also support electron delocalization in the silole ring of 3b. Dianion salt 3b underwent nucleophilic reactions with Me3SiCl and EtBr to form the corresponding disubstituted products. Benzaldehyde underwent reductive coupling in the presence of 3b. Slow oxidation of 3b yielded 1,1′dipotassio-1,1′-bis(silafluorene) (16). The X-ray structure and 29Si chemical shift (-38.0 ppm) of 16 indicate localized negative charges at the silicon atoms and no aromatic character. Heating a DME/hexane solution of 3b in the presence of 18-crown-6 led to a novel diradical dianion salt.
- Liu,Stringfellow,Ballweg,Guzei,West
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- SILICON-CONTAINING HETEROCYCLIC COMPOUNDS. LVII. DIRECT SYNTHESIS OF 9,9,10,10-TETRACHLORO-9,10-DISILA-9,10-DIHYDROANTHRACENE AND ITS DERIVATIVES
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In the direct synthesis of 9,9,10,10-tetrachloro-9,10-disila-9,10-dihydroanthracene (I), by the reaction of o-dichlorobenzene with a silicon-copper catalytic composition, several side processes occur due to thermal decomposition of the initial chloride at the Car-Cl and Car-H bonds on the surface of the catalyst and to subsequent interaction with it of the compounds formed.The degree of utilization of the catalyst in the direct synthesis of the heterocyclic compound (I) can be increased by its periodic treatment with hydrogen chloride or introduction of o-dichlorobenzene together with hexachlorodisilane into the reaction zone.
- Chernyshev, E. A.,Komalenkova, N. G.,Shashkov, I. A.
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p. 688 - 692
(2007/10/02)
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