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Fritz G, Keuthen M, Kirschner F, Matern E, Goesmann H, Peters K, Peters EM, Schnering HGV. Formation of organosilicon compounds 117:1 C-brominated 1,3,5-trisilacyclohexanes and their reactions with BuLi. CAN J CHEM 2000. [DOI: 10.1139/v00-035] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The photobromination of 1,1,3,3,5,5-hexamethyl-1,3,5-trisilacyclohexane (1) almost exclusively attacks CH2 groups and results in 2,2-dibromo-trisilacyclohexane (2) as well as 2,2,4,4-tetrabromo-trisilacyclohexane (3) in high yields. Starting from a mixture of C-brominated trisilacyclohexanes the isomeric 2,2,9-tribromo-1,3,3,5,5,8,8,10,10,13,13-undecamethyl-1,3,5,8,10,13-hexasilabicyclo[7.2.2]tridec-6-yne (6) had been obtained in very low yield in an attempt to establish a preparative route to adamantanes with a C4Si6 skeleton, i.e., with C bridgeheads and SiR2 bridges. By ICl-cleavage of a Simethyl bond in 2 and subsequent substitution with Br3CLi, the trisilacyclohexane 4 with functional groups in opposite positions of the ring can be obtained. Linking the step-by-step synthesized Cl-Me2Si-C=C-SiMe2-CH2-SiMe2-Ph to the CBr3 group of 4 results after HBr-cleavage of the SiPh bond in (ω-bromo-octynyl)-trisilacyclohexane (12). A ring closure of 12 would result in an isomeric hexasila bicyclo[7.2.2]tridec-6-yne. The compounds were characterized by 1H, 13C, and 29Si NMR spectra. Additionally, the molecular structures of 4 and 6 were confirmed by X-ray single crystal investigations.Key words: 1,1,3,3,5,5-hexamethyl-1,3,5-trisilacyclohexane, bromination, 2,2,9-tribromo-1,3,3,5,5,8,8,10,10,13,13-undecamethyl-1,3,5,8,10,13-hexasilabicyclo[7.2.2]tridec-6-yne, carbosilane synthesis, NMR data, crystal structure investigation.
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