Naokazu Kano

The polarity of a chemical bond is an important factor that affects its reactivity. We report here a method for reversing polarity of a hydrogen atom of water, which meant conversion of a proton (H+) to a hydride (H–), by using a hexacoordinated phosphorus species. Dihydrophosphate 2 was synthesized by the reaction of hydrophosphorane 1 with lithium naphthalenide, quenching with water, and cation exchange, successively. The hydrogen atoms on the phosphorus atom of 2 are not only exchangeable for a proton, but also usable as a hydride ion. The unique reactivity enables umpolung of deuterium of D2O and reductive deuteration of carbonyl compounds. The method is valuable for isotope-labeling of various compounds because the reaction proceeds under mild conditions and does not use transition metal. These results demonstrated the potential utility of non-metallic compounds for umpolung of a hydrogen atom.