催化Appel氟化：醇与氟化钾的转化

ORGaNic cheMistRY Catalytic Appel fluorination of alcohols with potassium fluoride Our goal was to invent an operationally simple Appel fluorination with inexpensive KF to shift the focus from designer reagents to innovative solutions, going as far as asymmetric catalytic variants. In this study, we disclose that alcohols are amenable to fluorination with KF and neopentoxyphosphonium salts under hydrogen bonding phase- transfer catalysis (Fig. 1B). The success of this chemistry stems from the forma- tion of a pentavalent neopentoxyfluorophosphorane undergoing alcohol exchange for subsequent C–F bond formation, notably in preference to PPh3F2 formation. The hydrogen bond donor catalyst serves multiple roles, not least offering a pathway to convert racemic alcohols into enantioenriched alkyl fluorides through a chiral ion–pairing strategy. …