np1c00512_si_001.pdf (3.73 MB)
Download file

Visible-Light-Promoted Biomimetic Reductive Functionalization of Quaternary Benzophenanthridine Alkaloids

Download (3.73 MB)
journal contribution
posted on 30.07.2021, 08:13 by Lin Wang, Xinhao Wang, Wei Wang, Wei Liu, Yisong Liu, Hongqi Xie, Oliver Reiser, Jianguo Zeng, Pi Cheng
Reduction of an iminium CN double bond is the most important phase I metabolism process associated with the cytotoxic property of quaternary benzophenanthridine alkaloids (QBAs). Inspired by the light-mediated reduction of QBAs with nicotinamide adenine dinucleotide, a visible-light-promoted reductive functionalization reaction of QBAs is reported in this study. C4-Alkyl-1,4-dihydropyridines (DHPs) enable the direct reductive alkylation of QBA independently, serving as both single-electron-transfer reductant reagents under irradiation with 455 nm blue light in the absence of photocatalysts and additional additives. Our protocol can be further applied to the semisynthesis of natural 6-substituted dihydrobenzo­phenanthridine derivatives such as O-acetyl maclekarpine E.