Tandem Catalysis:  The Sequential Mediation of Olefin Metathesis, Hydrogenation, and Hydrogen Transfer with Single-Component Ru Complexes

Organometallic catalysts are traditionally designed and optimized to mediate a single reaction. However, the increasing for expedient and efficient synthetic processes requires development of organometallic reagents that are capable of multiple, mechanistically distinct reactions directly or simple modification. While the Ru complex (PCy₃) ₂Cl₂Ru= (1) has found extensive use in olefin metathesis, it was recently shown to be an effective precatalyst for mediating additions and hydrogenation reactions. We recently all three reactions could be performed in tandem afford well-defined block copolymers. Herein, we report that 1, or its more active derivative 2, is also useful in a variety of other catalytic hydrogenation reactions that regiospecific ketone and olefin reductions, transfer of ketones, and dehydrogenative oxidations of. In addition, we demonstrate a variety of “one-pot” metathesis-hydrogenation procedures for the rapid of small molecules, including (R) - (-) -Muscone.