Catalyst@Metal Hybrids in a One-Pot Multistep Opposing Oxidation and Reduction Reaction Sequence

We report the feasibility of the catalysis of contrasting reactions, oxidation and reduction, in a multistep process that also involves a condensation reaction all performed with hybrids of catalytic organometallic complexes entrapped within metals ([complex]@metal). Two routes were explored for the multistep process. The first route used a combination of an oxidizing Ir complex entrapped in Ag ([Ir]@Ag) and a reducing Rh complex entrapped in Ag ([Rh]@Ag). The second route used a single composite material, namely, [Ir]@Pd, in which [Ir] acted as the oxidizing catalyst, and Pd was the reducing catalyst. Both routes were efficient for the heterogeneous catalytic oxidation and reduction reaction sequence. Towards the goal of a one-pot multistep oxidation and reduction process, a detailed study of the catalytic alcohol oxidation properties of the heterogeneous [Ir]@Ag and [Ir]@Pd was performed. As the arsenal of available hydrogenation catalysts exceeds by far that of oxidations, this part of the study is, we believe, of general interest in itself, as a new alternative to heterogeneous oxidative catalysis.