NSF-ANR-CHE: Catalyzed Dearomatization by Earth Abundant Metals – Cat-DrEAM

Aromatic compounds are important feedstock chemicals for many applications. As reagents, they most commonly function as a conduit to other aromatic structures; however, from the perspective of molecular complexity, transformations that convert the aromatic nucleus to chiral, non-aromatic structures are exceptionally valuable and challenging. Catalytic cyclopropanation of aromatic rings involving carbenoid addition represents an appealing neutral dearomatization strategy to create tridimensionality. Organometallic complexes based on rhodium occupy a privileged status within this subset of neutral dearomative reactions, exhibiting exceptional reactivity that is counterbalanced by the scarcity, increasing price, and environmental impact of such a transition metal. This circumstance simultaneously presents both an obstacle for sustainability and an opportunity for the development of new catalysts that are not reliant on rare metals. Whereas catalysts based on earth-abundant elements such as nickel, copper, iron, and cobalt offer tremendous promise for catalyzed alkene cyclopropanation reactions, the more challenging dearomatization reactions that convert aromatic feedstocks to value-added chiral chemicals are still in their infancy. The proposal builds on extensive expertise of the French and U.S. research teams in addressing myriad selectivity issues that are inherent to arene dearomatization, namely, site selectivity, diastereoselectivity, and enantioselectivity. The research plan builds on foundational preliminary results that provide support for the overall premise that earth-abundant metals can deliver results comparable to or superior to those seen with Rh(II).