Efficient and Selective Nitrile Hydration Reactions in Water Catalyzed by an Unexpected Dimethylsulfinyl Anion Generated in situ from CsOH and DMSO.

Unexpected dimethylsulfinyl anions (I), generated in situ from the superbase system CsOH–DMSO, was found to be a highly active catalyst for controllable nitrile hydration reactions in water, which selectively afforded the versatile amides via interesting Cs-activated I-catalyzed direct and indirect hydration mechanisms involving an O-transfer process from DMSO onto the nitriles.