Transition-Metal-Free Synthesis of C‑Glycosylated Phenanthridines via K2S2O8‑Mediated Oxidative Radical Decarboxylation of Uronic Acids
journal contributionposted on 20.12.2017 by Xin Zhou, Peng Wang, Li Zhang, Pengwei Chen, Mingxu Ma, Ni Song, Sumei Ren, Ming Li
Any type of content formally published in an academic journal, usually following a peer-review process.
We have developed an efficient protocol for the synthesis of C-glycosylated phenanthridines. Tetrafuranos-4-yl and pentapyranos-5-yl radicals, generated from K2S2O8-mediated oxidative decarboxylation of furan- and pyranuronic acids, undergo attack to 2-isocyanodiphenyls and ensuing homolytic aromatic substitution to provide diverse C-glycosylated phenanthridines in satisfactory yields without resort to transition metals. This reaction tolerates various functional groups, and enables ready synthesis of complex oligosaccharide-based phenanthridines. The C-glycosylated phenanthridine derived from β-cyclodextrin has been prepared, which might be potential in medicinal and biological chemistry due to its flexible conformation.