Alternative intermediates for glycerol valorization: iridium-catalyzed formation of acetals and ketals

The organoiridium derivatives [Cp*IrCl(2)], (Cp* = pentamethylcyclopentadienyl) and [Cp*Ir(Bu(2)-NHC)Cl(2)], (Bu(2)-NHC = 1,3-di-n-butylimidazolylidene) catalyzed glycerol acetalization with several ketones and aldehydes, as well as transacetalization. All the catalytic reactions produced the five-membered cyclic ketals, i.e. the 1,3-dioxolanes, as main products, with selectivities of 94-100% for ketals, and up to 83% for acetals.