Photoredox-catalyzed silyldifluoromethylation of silyl enol ethers
作者:Vyacheslav I Supranovich、Vitalij V Levin、Alexander D Dilman
DOI:10.3762/bjoc.16.126
日期:——
light-mediated fluoroalkylation of silyl enol ethers with (bromodifluoromethyl)trimethylsilane followed by a reduction of the primary products with sodium borohydride is described. An 18 W, 375 nm LED was used as the light source. The reaction is performed in the presence of a gold photocatalyst, which effects the generation of a (trimethylsilyl)difluoromethyl radical via cleavage of the carbon–bromine
Photoredox reactions are placed in sequence with asymmetrictransferhydrogenations of aryl ketones to provide chiral alcohols with enantioselectivities of up to 99 % ee. The method relies on a single chiral‐at‐metal iridium catalyst which is added at the beginning of the two step sequence and only a final purification of the reaction product is required.