Tryptanthrin with a broad spectrum of biological activities can be not only decorated by various functional groups, but also coordinated by bio-metal ions, generating varied tryptanthrin derivatives as potential anticancer agents with low toxicity.
A facile one-pot synthesis of natural alkaloid tryptanthrin and its derivatives from isatins catalyzed by CuI in the presence of KHCO3 has been developed.
The synthesis of sixteen tryptanthrin appended dispiropyrrolidine oxindoles, employing [3 + 2] cycloaddition of tryptanthrin-derived azomethine ylides with isatilidenes, and their detailed antibacterial evaluation is described.
An asymmetric formal [4 + 2] cyclisation between azlactones and aza-dienes derived from simple tryptanthrins has been developed. With this established protocol, yielding a series of novel piperidine-2-one-fused tryptanthrins with up to >99 : 1 er under mild conditions.
A class of ketimines was first prepared and used in an asymmetric aza-Friedel–Crafts reaction for the highly enantioselective synthesis of tryptanthrin derivatives.