Dehydrosilylation versus α-coupling in the electron-transfer of enol silyl ethers to quinones. Strong solvent effect on photogenerated ion pairs

Abstract

Time-resolved (picosecond) spectroscopy identifies the critical role of solvent polarity in modulating the ion-pair dynamics of the reactive intermediate [CTE˙⁺, CA˙^–] from the photoinduced electron transfer of cyclohexanone enol trimethylsilyl ether (CTE) and chloranil (CA) to yield selectively the dehydrosilylated enone 1 in dichloromethane but the oxidative adduct 2 in acetonitrile.