Utilization of a Trimethylsilyl Group as a Synthetic Equivalent of a Hydroxyl Group via Chemoselective C(sp³)-H Borylation at the Methyl Group on Silicon

A conversion of trimethylsilylalkanes into the corresponding alcohols is established based on an iridium-catalyzed, chemoselective C(sp³)-H borylation of the methyl group on silicon. The (borylmethyl)silyl group formed by C(sp³)-H borylation is treated with H₂O₂/NaOH, and the resulting (hydroxymethyl)silyl group is converted into a hydroxyl group by Brook rearrangement, followed by oxidation of the resulting methoxysilyl group under Tamao conditions. An alternative route proceeding through the formylsilyl group formed from a (hydroxymethyl)silyl group by Swern oxidation is also established. The method is applicable to substituted trimethylsilylcycloalkanes and 1,1-dimethyl-1-silacyclopentane for conversion into the corresponding stereodefined cycloalkyl alcohols and 1,4-butanediol.