CAREER: Ru and Cu Amido Complexes: Aryl Coupling, C-H Activation and C-N Multiple Bond Metathesis Reactions

North Carolina State University, Raleigh NC

Investigators

Abstract

This award by the Inorganic, Bioinorganic and Organometallic Chemistry program supports research by Dr. T. Brent Gunnoe of North Carolina State University to exploit low valent ruthenium and copper amido complexes to break and form bonds in transformations involving C-H and C-N bonds. For example, biaryl moieties are prevalent in an array of important compounds including natural products (e.g., terpenes, lignanes, flavonoids, coumarins, tannins and various alkaloids) as well as compounds for nonlinear optics, helical polymers, liquid crystals, ligands for asymmetric catalysis and for use in redox reactions. The leading methods for preparation of biaryl linkages involve cross coupling between aryl halogen and organometallic aryl species; however, such reactions often suffer from the requirement of multi-step syntheses of aryl halide and aryl organometallic reagents, and, in some cases, the use of organometallic aryl compounds results in the stoichiometric production of toxic byproducts. The proposed chemistry seeks to study the details of ruthenium and copper-mediated C-C coupling reactions that proceed via cleavage of C-H bonds. Oxidation of well-defined ruthenium and copper amido complexes promotes such reactions, and both detailed mechanistic studies and possible extension to catalytic sequences will be pursued. In addition, the synthesis of polymers that contain heteroatomic functionality is of current interest due to the ability to control macroscopic properties. Ruthenium amido complexes have been used to cleave C-N multiple bonds, and the proposed chemistry will explore these reactions in detail including possible extension to polymerization methodologies. The teaching plan describes a range of activities in both undergraduate and graduate instruction including revision of the departmental curriculum and upper level courses, working toward increased research opportunities for undergraduates, and integration of a program into the graduate curriculum that: (1) incorporates a graduate student-based outreach program to schools (grades 6th - 8th) whose populations are comprised primarily of groups that are underrepresented in the sciences (2) exposes graduate students to current topics of research ethics and (3) provides graduate students with a guided teaching experience. The proposed chemistry seeks to exploit the reactivity of metal complexes for the construction of small organic molecules that form the foundation for many useful products. The teaching plan involves both undergraduate and graduate instruction including revision of the departmental curriculum and upper level courses, increasing research opportunities for undergraduates and outreach to local schools.