Partial Deoxygenation of Glycerol Catalyzed by Iridium Pincer Complexes

Iridium pincer complexes (POCOP)­Ir­(CO) (POCOP = κ3-C6H3-1,3-[OP­(tBu)2]2) and substituted POCOP derivatives catalyze deoxygenation of glycerol to n-propanol and 1,3-propanediol in good yield under moderate conditions (acidic aqueous dioxane, 200 °C, 80 bar H2). Catalyst solubility in the polar reaction mixture is improved by incorporation of a polar moiety in the para position of the POCOP phenyl ring, with the best results obtained with a dimethylamino substituent.