The Nicewicz Lab is focused on the discovery of new and powerful reaction methodologies that proceed via the intermediacy of highly reactive cation radical species. Included in these transformations are anti-Markovnikov selective additions of amines, alcohols, carboxylic acids, amides and mineral acids to alkenes. The key reactive intermediates, alkene cation radicals, are generated via single electron oxidation by photoexcited acridinium salts, first developed by Shunichi Fukuzumi. A range of acridinium catalysts have been established for this purpose, all of which are air and moisture stable and have oxidizing capabilities all significantly higher (>+2.0 V vs. SCE) than their Ru- and Ir- polypyridyl counterparts. Excitation of the acridinium salts can be accomplished easily in batch or in flow using 450 nm LED flood lamps. In conjunction with either thiol or disulfide co-catalysts, anti-Markovnikov additions of acids to styrenes, trisubstituted aliphatic alkenes and enamides are possible. If allylic alcohols or α, β-unsaturated carboxylic acids are partnered with alkenes, highly substituted tetrahydrofurans and butyrolactone products can be formed, respectively, via polar radical crossover cycloadditions. The Nicewicz Lab continues to develop new transformations based on the generic acridinium catalyst platform with the goal of operational simplicity.
Nicewicz Group Website