RUI: New Synthetic Methods for CB11 Carboranes

Whitman College, Walla Walla WA

Investigators

Abstract

The Chemical Synthesis Program of the Chemistry Division supports the project by Professor Marcus Juhasz. Professor Juhasz is a faculty member in the Department of Chemistry at Whitman College. He investigates molecules constructed from a stable core cluster of boron atoms. These molecules have unique properties that have long been of interest for the development of new therapeutic and imaging agents for medicinal applications, new catalysts for industrially-important chemical reactions, and new advanced optical and electronic materials. Yet in spite of this interest, the molecules have seen limited use. This is in large part because of a lack of synthetic methods that allow for their preparation. The goal of the research being pursued by Professor Juhasz and his group is to solve this problem. Accordingly, they are working to develop efficient approaches for the preparation of new boron clusters. In addition to these scientific goals, the reactions being developed provide excellent opportunities to educate science students in the subfields of organic and inorganic chemistry. The chemistry has the potential for high impact, and it is accessible to the undergraduates who are driving the effort. As a teacher-scholar at a small undergraduate institution, Professor Juhasz is well positioned to train and closely mentor students who are underrepresented in science. The anionic boron cluster CHB11H11- (CB11) is a very stable molecule whose derivatives are attractive for a variety of applications, including catalysis, medicine, and advanced materials. Synthetic methods for producing derivatives of CB11 have remained largely unexplored. The overarching goal of this proposal is to develop new synthetic methods for preparing useful derivatives of CB11, by pursuing three specific synthetic aims. Aim 1 is introducing ester and amide functional groups at boron vertices employing a two-step synthesis with a carboxylic acid intermediate to attach amides and esters to boron atoms in the CB11 cage. Aim 2 is expanding an existing cyanation strategy (through optimization of the catalyst, solvent, and microwave-irradiation parameters) to prepare highly cyanated CB11 clusters. Aim 3 is developing a versatile method for introducing alkyl and aryl substituents via an adapted Suzuki coupling reaction. The proposed is preparing potentially useful derivatives of CB11 carborane clusters. Moreover, this project is providing a high level of training and education for future scientists by immersing undergraduate students in cutting-edge research in synthetic organic and inorganic chemistry. 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.