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DOI: 10.1055/s-0030-1258055
Base-Catalyzed Dehydrogenative Si-O Coupling of Dihydrosilanes: Silylene Protection of Diols
Publikationsverlauf
Publikationsdatum:
19. August 2010 (online)
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Abstract
The direct dehydrogenative coupling of 1,3- and 1,4-diols and dihydrosilanes is efficiently catalyzed by Cs2CO3 (10 mol%), cleanly affording six- and seven-membered 1,3-dioxo-2-silacycles with dihydrogen as the sole by-product. Conversely, 1,2-diols do not yield the expected 1,3-dioxo-2-silacyclopentanes, essentially forming cyclic disiloxanes instead. Aside from the synthetic convenience, the procedure itself is also useful for straight-forward diol derivatization prior to GLC analysis.
Key words
coupling - dehydrogenation - diols - protecting groups - silicon
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- Supporting Information
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References and Notes
General Procedure for Silylene Protection A flame-dried Schlenk flask was charged with Cs2CO3 (10 mol%). The flask was evacuated and backfilled with argon prior to the successive addition of the diol (1.0 equiv) dissolved in THF (0.15 M) and the dihydrosilane (1.2 equiv) dissolved in THF (0.50 M). The reaction mixture was maintained at r.t. for the indicated time, and the base was then filtered off. The filtrate was evaporated under reduced pressure, affording the crude silylene-protected diols, which were purified by flash column chromatography on silica gel.
16The reaction of Ph2SiH2 with H2O in the absence of base yields disiloxane (Ph2HSi)2O (cf. ref. 8).