CAS: Catalytic Carbonylation and C-H functionalization Reactions with Rhenium Complexes

North Carolina State University, Raleigh NC

Investigators

Abstract

With the support of the Chemical Catalysis (CAT) and the Chemical Synthesis (SYN) Programs in the Division of Chemistry, Professor Elon Ison of North Carolina State University will study the direct carbonylation of C–H bonds by transition metal catalysts and the direct double carbonylation of C–H bonds. Catalysis is widely recognized as an important tool in the continued effort to minimize waste and in the effort to utilize chemical feedstocks more efficiently. The proposed experimental approach will be complemented and guided by computational chemistry to assist in identifying the limitations of elementary steps in the proposed catalytic cycles and to inform synthetic choices for the preparation of improved catalysts using rhenium as the central metal. The program integrates the concepts of sustainable chemistry and catalysis into the training and teaching of graduate and undergraduate students, postdoctoral associates, and high school students. The research program incorporates important elements of mechanistic chemistry including the integration of computational methods at the high school and undergraduate levels, and the incorporation of catalysis and sustainable chemistry into undergraduate teaching laboratory programs. To achieve research goals of the project, Professor Ison and his team will pursue the following specific aims: (i) examination of the activation of C–H bonds by rhenium (III) acetate complexes, (ii) understanding mono- and double carbonylation reactions with rhenium complexes, and (iii) development of a rhenium catalyst for double and mono-carbonylation reactions and other C–H functionalization reactions. These studies will probe whether a concerted metalation-deprotonation reaction mechanism provides a viable pathway for the rhenium-mediated C–H activation reaction. The pursuit of rhenium-catalyzed double carbonylation reactions is of particular interest to these studies as this transformation is relatively uncommon, but potentially of high impact, if better understood. The target products are expected to be important chemical building blocks present in many natural products and pharmaceuticals that display important biological activity. The viability of the Re-mediated reactions will be investigated computationally and experimentally. Given the unusual reaction pathways described and the longstanding interest in carbonyl insertion into metal-acyl bonds, this research is expected to be of broad interest to the inorganic and organometallic chemistry communities and will likely offer insight into the design of new catalytic systems. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.