Pentafluorophenyl Esters: Highly Chemoselective Ketyl Precursors for the Synthesis of α,α-Dideuterio Alcohols Using SmI2 and D2O as a Deuterium Source.

We report the first highly chemoselective synthesis of α,α-dideuterio alcohols with exquisite incorporation of deuterium (>98% [D2]) using pentafluorophenyl esters as ketyl radical precursors, SmI2 as a mild reducing agent, and D2O as the deuterium source. This system tolerates a variety of functional groups, offering rapid entry to valuable α,α-dideuterated alcohol building blocks. More generally, this report introduces pentafluorophenyl esters as the most reactive O-ketyl precursors reported to date.