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.

pH-Dependent catalytic activity and chemoselectivity in transfer hydrogenation catalyzed by iridium complex with 4,4'-dihydroxy-2,2'-bipyridine.

Transfer hydrogenation catalyzed by an iridium catalyst with 4,4'-dihydroxy-2,2'-bipyridine (DHBP) in an aqueous formate solution exhibits highly pH-dependent catalytic activity and chemoselectivity. The substantial change in the activity is due to the electronic effect based on the acid-base equilibrium of the phenolic hydroxyl group of DHBP. Under basic conditions, high turnover frequency values of the DHBP complex, which can be more than 1000 times the value of the unsubstituted analogue, are obtained (up to 81 000 h(-1) at 80 degrees C).

Recyclable catalyst for conversion of carbon dioxide into formate attributable to an oxyanion on the catalyst ligand.

The catalyst recycling in the conversion of CO2 into formate using the iridium complex with 4,7-dihydroxy-1,10-phenanthroline as a catalyst precursor is described. The catalyst precursor was dissolved in an aqueous KOH solution under CO2 pressure prior to the reaction, but was precipitated spontaneously at the end of the reaction. The acidification by the generation of formate caused the transformation from the water-soluble deprotonated form into the water-insoluble protonated form.