Fluorinated Pseudo-Tetrahedral Complexes as Robust Platforms for Multiply Bonded Ligands and Group Transfer Reactivity"

With the support of the Chemical Synthesis program in the Division of Chemistry, John Anderson of the University of Chicago will study new oxidatively robust transition metal complexes that enable the transfer of reactive oxygen-, nitrogen-, and carbon-based organic fragments to substrates. There has been a continued interest worldwide in generating and isolating examples of such transition metal complexes capable of these organic group transfers, with the goal of improving catalytic efficiency and selectivity for reactions of importance to renewable energy, chemical industry, and pharmaceutical development. However, such complexes are often difficult to isolate and characterize due to their very high reactivity. In this research, the Anderson group will address this challenge by designing and synthesizing a robust new ligand scaffold which will not engage in degradation, but which will still support highly reactive intermediates, thus facilitating the study of these highly reactive species. Dr. Anderson will institute an integrated plan to recruit and support talented scholars from underrepresented groups in the sciences. He will pursue efforts with outreach to local elementary schools on the south side of Chicago, as well as in providing research-based internships for high school students. He will also work to establish and sustain an undergraduate research program for first-generation college students. Under this award, the Anderson group will build on their prior synthesis of a prototypical perfluoroalkyl ligand scaffold to develop a class of oxidatively robust ligand frameworks containing strongly donating carbenes that stabilize late-transition metal oxo complexes with pseudo-tetrahedral geometries. The synthesis strategy will enable the observation and study of extremely reactive high-valent intermediates, as well as discover more efficient catalysts for the important class of group transfer reactions involving oxo/nitrene/carbene moieties. The project involves the synthesis of late transition metal oxo complexes supported by fluorinated carbene ligands, measurements of the physical properties of these species including their redox potentials and basicities, characterization of the nucleophilic/electrophilic/radical reactivity of these species, and delineation of their stoichiometric and catalytic group transfer reactions. The expected molecular and mechanistic insights from this research will enable not only a better understanding of group transfer reactivity, but also assist in the design of optimized catalysts for this important class of transformations. 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.