Catalytic (transfer) deuterogenation in D2O as deuterium source with H2 and HCO2H as electron sources.

Deuterium-labelled compounds were prepared by (transfer) deuterogenation of unsaturated compounds using H(2) or HCO(2)H in acidic D(2)O as deuterium source with almost quantitative yields and high deuterium contents under mild reaction conditions via heterolytic cleavage of H(2) (or decomposition of HCO(2)H) and rapid H(+)/D(+) exchange using iridium catalysts with 4,4'-dihydroxy-2,2'-bipyridine.