Chemistry Weekly Seminar - Dennis Hall, University of Alberta
Dennis Hall, Professor in the Faculty of Science-Chemistry, University of Alberta, will present a seminar at 1:30 pm in ARTS 146.
Title
From Drugs to Catalysts: Design, Properties and Application of Cyclic Hemiboronic Acids
Abstract
The successful development and commercialization of the benzoxaborole drugs tavaborole and crisaborole has initiated a renaissance surrounding heterocycles derived from boronic acids in organic and medicinal chemistry. These new drugs, along with other cyclic hemiboronic acids, demonstrate a wide range of biological properties such as antifungal, antibacterial, and anti-inflammatory activity. Despite the success of these boroheterocycles, many questions remain unanswered regarding the desirable physical properties and the dynamic behavior of boranol (BOH)-containing heterocycles in aqueous media. Likewise, a precise knowledge of their acidic nature (Lewis vs Brønsted) is crucial toward tailoring their uses.
In the past few years, this laboratory has investigated several classes of hemiboronic heterocycles providing a comprehensive evaluation of their structure, stability, chemical and physical properties.1-2 To resolve decades of conflicting views on the acidic and aromatic characteristics of pseudoaromatic hemiboronic acids, a multipronged experimental and computational approach was employed. These fundamental studies can help guide a systematic application of select boroheterocycles as enantioselective reaction catalysts,3 in bioconjugation, and as new drug chemotypes and bioisosteres of pharmaceutically important classes of heterocycles. In recent work, benzoxaborine derivatives were identified as modular scaffolds enabling both nucleophilic and electrophilic activation of alcohols, which was exemplified in the monophosphorylation of diols, and the reduction of pi-activated alcohols and ketones with silanes under ambient conditions, respectively.
References
1. Kazmi, M. Z. H.; Rygus, J. P. G.; Ang, H. T.; Paladino, M.; Johnson, M. A.; Ferguson, M.; Hall, D. G. J. Am. Chem. Soc. 2021, 143, 10143–10156.
2. Ang, H. T.; Ponich, A. A.; Paladino, M.; Miskolzie, M.; Hall, D. G. J. Am. Chem. Soc. 2022, 144, 10570–10581.
3. Estrada, C. D.; Ang, H. T.; Vetter, K.-M.; Ponich, A. A.; Hall, D. G. J. Am. Chem. Soc. 2021, 143, 4162–4167.
Date: Friday, November 18, 2022
Time: 1:30 pm
Place: Arts 146