Ambiphilic Phosphines Based on Redox-Active Carborane Clusters

With the support of the Chemical Synthesis (SYN) program in the Division of Chemistry, Professor Dmitry Peryshkov of the University of South Carolina at Columbia is studying the development of metal-free reagents and catalysts for the functionalization of organic compounds. This project will focus on a novel approach to catalysis, the process that underpins the production of the majority of manufactured chemical products, including polymers and pharmaceuticals. Traditionally, many chemical processes depend on precious metals like ruthenium, rhodium, and palladium, which are expensive, scarce, and often toxic. Professor Peryshkov will investigate and design the principles to replace these metals with metal-free systems that can carry out similar chemical transformations in a more sustainable and cost-effective way. These new non-metal reagents will be designed to be "ambiphilic," meaning they can both donate and accept electrons. This dual ability will mimic the behavior of transition metal catalysts and allow breaking and making of chemical bonds in a way typically reserved for metals. This project will involve the use of advanced inorganic and organic synthetic techniques as well as theoretical chemistry methods and will serve as a foundational training ground for undergraduate and graduate students to prepare them for the entry into the future science and technology workforce. The team of graduate and undergraduate students led by Professor Peryshkov will carry out the synthesis of the novel phosphines decorated with boron cluster groups and study of their ambiphilic reactivity. The ability of boron clusters to accepts electrons will be the key to impart electrophilic behavior onto normally nucleophilic trigonal phosphorus centers. The activation of N-H and B-H bonds in metallomimetic manner by the redox-active phosphines will open a pathway for metal-free sustainable new reactions such as hydroboration and hydroamination of unsaturated substrates. Furthermore, the new ambiphilic phosphines will be explored as new reagents for important chemical processes such as cyanation and azidation. A major objective will be to design these systems to be recyclable and catalytic. The properties of ambiphilic phosphines will be controlled via chemical changes to their modular structure. 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.