Arylation of α‐Imino Ketones and their Cyclization with Allenoates: Direct Access to Sterically Hindered Pyrroles

Abstract Herein, we report a calcium‐catalyzed, one‐pot, four‐component reaction to synthesize diversely substituted pyrroles. This atom‐economy reaction involves a sequence of reactions that proceed via in situ formation of α ‐ imino ketones, Friedel‐Crafts arylation, aza‐cyclization, and aromatization in the single pot. The reaction showed a broad substrate scope with good yields. We demonstrated the gram‐scale synthesis and post‐synthetic modifications.