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DOI: 10.1055/s-2008-1032078
DBU-Promoted Facile, Chemoselective Cleavage of Acetylenic TMS Group
Publikationsverlauf
Publikationsdatum:
12. Februar 2008 (online)
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Abstract
Acetylenic trimethylsilyl (TMS) groups were efficiently removed using 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU). With either 1.0 or even 0.1 equivalents of DBU, smooth desilylation of various terminal acetylenic TMS groups was accomplished selectively in the presence of alkyl silyl ethers and other base-labile groups. Furthermore, more sterically hindered terminal acetylenic silyl groups such as TBDMS and TIPS remained intact under these conditions.
Key words
DBU - silylacetylene - chemoselective - deprotection
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References and Notes
A Representative Procedure the Desilylation of Acetylenic TMS
To a magnetically stirred solution of 1 (195 mg, 0.563 mmol) in MeCN (1.1 mL) and H2O (56 µL) were added DBU (84 µL, 0.563 mmol) at r.t. The mixture was heated to 60 °C, and the stirring was continued for 40 min. After completion of the reaction, the resulting residue was concentrated under reduced pressure and purified by passing through a short silica gel column (ca. 5 cm) to afford pure alkyne (155 mg, 99% yield).
Determined from GC analysis using HP-5 column (crosslinked 5% PH ME polysiloxane).