SusCHEM: New Redox-Active Pincer Ligands for Sustainable Base Metal Cross Coupling Catalysis

Georgia Tech Research Corporation, Atlanta GA

Investigators

Abstract

With this award, the Chemical Catalysis Program of the Division of Chemistry is funding Professor Jake Soper of the Georgia Institute of Technology to develop new sustainable, inexpensive and environmentally benign catalysts for the formation of carbon-carbon bonds. Selective carbon-carbon bond forming reactions are important for the synthesis of pharmaceuticals, specialty and commodity chemicals, materials, and fuels. Most state-of-the-art catalysts for carbon-carbon bond forming reactions are based on expensive and rare precious metals, such as palladium, platinum and iridium, and routes to carbon-carbon bonds often require toxic or expensive precursor molecules. This project is addressing both of these issues by developing catalysts based on more abundant and benign metals, such as iron, cobalt, and nickel. To accomplish this goal, Professor Soper's team is developing new ligands, to bind the base metal centers and impart the desired reactivity. The research team includes high school students, undergraduate students, graduate students, and high school chemistry teachers. In addition, an educational outreach program is developing a series of online education modules with accompanying demonstrations, experiments and in-class discussions for Atlanta AP chemistry classrooms. Redox-active ligands can bring about precious metal-like organometallic reactions at later 3d transition metals. With this award, Professor Soper is preparing new pincer-type redox-active ligands that harness these ligand-mediated redox steps for functional base metal cross coupling catalysis. Target reactions include cobalt-catalyzed cross coupling of alkyl ether electrophiles and iron, cobalt and nickel-catalyzed aerobic dehydrogenative carbon-carbon cross coupling via direct carbon-hydrogen activation. All of these coupling reactions address issues of sustainability by replacing palladium with base metal catalysts that are inexpensive and environmentally benign, as well as replacing halogen-containing stoichiometric oxidants and pre-functionalized substrates with dioxygen and carbon-hydrogen bonds, respectively.