Umpolung of a Hydrogen Atom of Water by Using a Hexacoordinated Phosphate and Its Application to Deuteride Reduction Reactions of Carbonyl Compounds

The polarity of a chemical bond is an important factor that determines the reactivity because a reaction of a positively charged atom with a negatively charged atom easily occurs. We report here a method for reversing the polarity of a hydrogen atom of water, which meant conversion of a protic hydrogen (H(delta+)) to a hydridic hydrogen (H(delta-)), by using a hexacoordinated phosphorus species. The method enables a reductive deuteration of carbonyl compounds utilizing inexpensive and easily usable D2O under mild conditions. The umpolung of a hydrogen atom was achieved by utilizing tautomerization of phosphorus compounds. Classical metal hydrides never have this function, and these results demonstrated the potential utility of nonmetallic compounds for umpolung of a hydrogen atom.