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

Abstract

The organoiridium derivatives [Cp*IrCl2]2 (Cp* = pentamethylcyclopentadienyl) and [Cp*Ir(Bu2-NHC)Cl2], (Bu2-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.