The NSF Chemical Catalysis Program supports the efforts of Professor Timothy H. Warren of Georgetown University in the design and development of new protocols for carbon-nitrogen (C-N), carbon-oxygen (C-O), and carbon-carbon (C-C) bond formation. This research is propelled by a detailed understanding of the key carbon-hydrogen (C-H) activation and C-functional group (C-FG) bond forming reactions to motivate new catalyst architectures for tunable selectivity. The team develops C-H amination reactions with unactivated amines, C-H etherification with alcohols and protected phenols, C-H nitroalkylation with nitroalkanes, and C-H alkylation with ketones as well as C-FG forming reactions via other H-FG substrates. They synthetically and mechanistically examine key copper(II)-FG intermediates to understand their roles in C-FG bond formation and H-atom abstraction reactions. These chemists examine new ligand variations to enhance the lifetime of particularly reactive copper(II)-FG intermediates as well as to direct the C-FG bond forming step. A wide range of synthetically valuable, mechanistically related C-H functionalization reactions address important challenges in sustainable chemical synthesis, such as the conversion of hydrocarbons to amines using ammonia. This research falls under the "SusChEM" initiative as it promotes the use of non-precious metal catalysts - copper - over more rare and expensive alternatives. Collaboration with Merck allows Georgetown students to access the Merck Catalysis and Automation Laboratory in Rahway, NJ. At the Merck laboratories, the students employ high throughput approaches to the discovery of new C-H functionalization catalysts and catalytic transformations. Ongoing collaborations with Prof. Karsten Meyer (U. Erlangen, Germany) and with Prof. Tom Cundari (U. North Texas) enable in depth spectroscopic studies and computational insights, respectively. Through the organization "Higher Achievement", Professor Warren connects with high-risk middle school students from low income families in under-resourced communities, providing fun science programming to their middle school scholars in a Chemistry Show (90-100 students) held at Georgetown each summer as well as at least one smaller visit (10-20 students) to Georgetown during each academic year when DC public schools are closed.
The NSF Chemical Catalysis Program supports the efforts of Professor Timothy H. Warren of Georgetown University in the design and development of new protocols for carbon-nitrogen (C-N), carbon-oxygen (C-O), and carbon-carbon (C-C) bond formation. This work addresses valuable and sustainable chemical synthesis, such as the conversion of hydrocarbons to amines using ammonia. The development of new methodologies for bond formation with carbon that eliminate the need for specific substrates and protection / deprotection steps can accelerate organic chemical synthesis as well as enhance industrial throughput - all while reducing the environmental footprint and enhancing the sustainability of chemical synthesis. While many C-H functionalization systems employ palladium and other noble metals, this approach employs copper - an Earth-abundant metal of low cost and toxicity. Industrial collaborations allow graduate students to explore high throughput approaches to discovery while increasing their own job marketability. Ongoing collaborations within the U.S. and in Germany also provide students with the broader perspective of performing research in a global community, enhancing both their technical and teamwork skills. Professor Warren and his group connect with high-risk middle school students from low income families in under-resourced communities, providing science programming via a Chemistry Show each summer as well as during occasional smaller visits to Georgetown Univeristy held when District of Columbia public schools are closed.
