Tricyclic Aza-Andrographolide Derivatives from Late-Stage Hydroamination and Their Anti-human Coronavirus (Anti-HCoV) Activity

A late-stage functionalization
(LSF) of the natural product andrographolide
for the efficient assembly of a range of structurally interesting
and diverse tricyclic-aza derivatives was developed. The key to the
diversification is a photo-catalyzed intramolecular hydroamination
reaction, and acridinium derivatives were demonstrated to be the optimal
catalysts. Additionally, the synthesized tricyclic aza-andrographolide
derivatives were found to inhibit human coronavirus with high potency.