Regeneration of an Iridium(III) Complex Active for Alkane Dehydrogenation Using Molecular Oxygen

Abstract

(dmPhebox)Ir(OAc)2(OH2) (1a) has previously been found to promote stoichiometric alkane dehydrogenation, affording alkene, acetic acid, and the corresponding Ir hydride complex (dmPhebox)Ir(OAc)(H) (2a) in high yield. In this study, we describe the use of oxygen to quantitatively regenerate 1a from 2a and HOAc. Distinct reaction intermediates are observed during the conversion of 2a to 1a, depending upon the presence or absence of 1 equiv of acetic acid, highlighting potential mechanistic implications regarding alkane dehydrogenation catalysis and the use of oxygen as an oxidant in such systems.