Vanadium(V) Complex-Catalyzed One-Pot Synthesis of Phenanthridines via a Pictet-Spengler-Dehydrogenative Aromatization Sequence

Abstract

Phenanthridine and its derivatives are important structural motifs that exist in natural products, biologically active compounds, and functional materials. Here, we report a mild, one-pot synthesis of 6-arylphenanthridine derivatives by a sequential cascade Pictet-Spengler-dehydrogenative aromatization reaction mediated by oxovanadium(V) complexes under aerobic conditions. The reaction of 2-(3,5-dimethoxyphenyl)aniline with a range of commercially available aryl aldehydes provided the desired phenanthridine derivatives in up to 96% yield. The ability of vanadium(V) complexes to function as efficient redox and Lewis acid catalysts enables the sequential reaction to occur under mild conditions.

Keywords

• phenanthridines
• catalysis
• Pictet-Spengler
• Lewis acid
• heteroarenes
• dehydrogenative aromatization