Predictable site-selective radical fluorination of tertiary ethers
作者:Junyang Ma、Wentao Xu、Jin Xie
DOI:10.1007/s11426-019-9636-8
日期:2020.2
site-selective radical fluorination of readily available tertiaryalkyl ethers, enabled by synergistic photocatalysis and organocatalysis. This catalytic combination allows for exclusive fluorination of tertiary C-O bonds under mild conditions even in the presence of competing reaction sites. The excellent functional group tolerance affords valuable access to sterically hindered alkyl fluorides through
the direct conversion of benzylicC-H groups to C-F. We show that visible light can activate diarylketones to abstract a benzylic hydrogen atom selectively. Adding a fluorine radical donor yields the benzylicfluoride and regenerates the catalyst. The selective formation of mono- and difluorination products can be achieved by catalyst control. 9-Fluorenone catalyzes benzylicC-H monofluorination, while