Trideuteromethylation Enabled by a Sulfoxonium Metathesis Reaction

A conceptually novel sulfoxonium metathesis reaction between TMSOI and cost-effective DMSO-d ₆ is developed for the efficient generation of a new trideuteromethylation reagent TDMSOI. The new reagent TDMSOI is produced highly efficiently by simply heating a mixture of TMSOI and DMSO-d ₆ and directly used for subsequent trideuteromethylation in a "one-pot" operation. The preparative power of the new versatile reagent and the "one-pot" protocol is demonstrated by its use to install the ?CD ₃ moiety into broad functionalities including phenols, thiophenols, acidic amines, and enolizable methylene units in high yield and at a useful level of deuteration (>87% D).