Peterson H.J., et al. Tetrahedron, 2025, 171, 134418.
Tetrabutylammonium difluorotriphenylsilicate (TBAT) has been effectively applied as a catalyst in the synthesis of cyclic dioxasilinanes from β-hydroxy ketones. In the described procedure, a β-hydroxy ketone (0.567 mmol) was reacted with diphenylsilane (0.567 mmol) in the presence of p-xylene as an inert internal standard. A solution of TBAT (0.42 M in THF, 0.272 mL, 0.2 equiv.) was then added, and the reaction mixture was stirred for 1 hour. The crude product was purified by column chromatography using florisil as the stationary phase and a gradient elution from 10:1 to 4:1 hexanes/ethyl acetate, yielding the dioxasilinane as a colorless oil.
Unlike conventional methods requiring prior silyl ether formation, the TBAT-catalyzed reaction proceeds directly, promoting both silyl ether formation and subsequent intramolecular hydrosilylation. This streamlined approach affords dioxasilinanes with notable diastereoselectivity, consistent with an intramolecular reaction mechanism. The resulting dioxasilinanes are sufficiently stable to permit isolation and further functionalization, such as regioselective opening with methyllithium to generate differentiated 1,3-diols selectively protected as diphenylmethylsilyl ethers.
