Mechanism of the Reduction of Ketones by Trialkylsilane. Hydride Transfer, SET-Hydrogen Atom Abstraction, or Free Radical Addition

Article abstract of DOI:10.1021/jo00362a019

The mechanism for the fluoride ion catalyzed reduction of ketones with phenyldimethylsilane was investigated.With reactive substrates (i.e., α,α,α-trifluoroacetophenone) the silane can act as a reducing agent to give, upon hydrolysis, moderate yields of the corresponding alcohol.The pentavalent anion formed from the silane and fluoride anion is, as had been previously reported, an excellent hydride reducing agent and even with moderate acceptors (i.e., α-fluoroacetophenone and cyclopropyl phenyl ketone) the anion acts as a SET reagent to give minor amounts of radical derived reduction products.