Copper‐Catalyzed α‐Indolmethylation of 2‐Pyridylacetates with 3‐Indoleacetic Acids via Alkylideneindolenine Intermediates

Abstract This study reports the copper‐catalyzed α‐indolmethylation of 2‐pyridylacetates with 3‐indoleacetic acids. This reaction offers an approach to generating alkylideneindolenine electrophiles via the oxidative decarboxylation of 3‐indoleacetic acids. The developed reaction system demonstrates good versatility, extending beyond the indolmethylation of 2‐pyridylacetates to include activated esters and nitroalkanes. Moreover, a biological evaluation revealed that several products exhibited antiproliferative activity against different cancer cell lines.