Hunanamycin A (HA), isolated from Bacillus hunanensis by MacMillan and co-workers, exhibits antibacterial activity against Gram-negative pathogens such as Salmonella and Escherichia coli. Demand for antibacterial compounds is increasing as bacteria become more resistant to available antibiotics. To further explore HA and structurally related compounds, our project aims to optimize the synthesis of 3,4-dihydro-2(1H)-quinolinone derivatives. Through preparing α,β-unsaturated amides as starting material for Lewis acid catalyzed cyclization, the quinoline core structures of 8-bromo-4,4-dimethyl-3,4-dihydroquinolin-2(1H)-one and 4,4-Dimethyl-3,4-dihydroquinolin-2(1H)-one were synthesized in 41 and 68 % yield, respectively. This route provides access to a variety of quinoline core structures.
Photoredox catalysis (PRC), utilizing light energy and transition metals to control single-electron transfer reactions, can produce substituted cyclobutanes, as well as many other structural motifs. Natural products containing cyclobutane rings often exhibit antiviral, antifungal, and anticancer activity; methods allowing for efficient entry into related molecular structures are of potential value. By creating a small library of olefins via a two-step synthetic route from 1-indones and tetralones, we have initiated studies toward exploring the substrate scope and limitations of Ruthenium PRC in the context of [2+2] cycloadditions. Building on the work of Chen et al. Ru(bpy) and Ru(bpm) will be initially screened against a small library of olefins.
