SusChEM: Advancing Organoelement Synthesis through alpha Elimination and Hydrophosphination Catalysis

University Of Vermont & State Agricultural College, Burlington VT

Investigators

Abstract

The Chemical Catalysis Program of the Chemistry Division supports the project by Professor Rory Waterman. Professor Waterman is a faculty member in the Department of Chemistry at the University of Vermont. The objective of this proposal is to discover and understand catalytic reactions that form phosphorus-carbon and silicon-carbon bonds. Central to meeting that objective is utilizing abundant metals as catalysts to afford divergent chemical reactivity of phosphorus-hydrogen and silicon-hydrogen bonds with a variety of reagents. Two specific reactions will be explored: alpha elimination and hydrophosphination. Alpha elimination is a rare and relatively new reaction with the potential to facilitate the synthesis of complex molecular structures. These structures have applications in materials science, catalysis, and biomedicine. Hydrophosphination is a well-established transformation, but questions and limitations remain. Overcoming these challenges makes this reaction available for broader use in the synthesis of pharmaceuticals, for example. Improved understanding in both reactions would advance the multi-billion dollar field of catalysis. Professor Waterman has been able to successfully recruit students underrepresented in the sciences, provide research experiences for high school students, and engage in educational outreach with K-12 students, practices to be continued in this project. The proposal explores two unique kinds of catalysis to understand and improve the catalytic preparation of E- carbon (C) (E = phosphorus or silicon) bonds, recognizing that abundant and inexpensive metals can be enlisted to produce divergent reactivity upon E-hydrogen (H) bond activation in the presence of unsaturated substrates. Through a series of testable hypotheses, a validated set of design features for alpha elimination catalysis is sought. This reaction may result in the efficient synthesis of phosphorus- and silicon-containing molecules via catalytic E-C bond formation is a key driver. Prior discoveries in this group demonstrate that such new reactivity is possible, and efforts in this area seek to improve understanding of M-E bonding and reaction chemistry. Efforts to discover new and highly efficient syntheses of chiral-at-phosphorus ligands though hydrophosphination provide a platform to address those fundamental issues and broaden the understanding and utility of this key P-C bond forming reaction. Beyond the benefit of these reactions to fields such as materials science, energy, and biomedicine, the outreach program includes direct research experiences for high school students in support of project goals.