One‐Pot Trimetallic Relay Catalysis: A Unified Approach for the Synthesis of β‐Carbolines and Other [ c ]‐Fused Pyridines

A divergent strategy is presented for the synthesis of 1,3‐di‐ and 1,3,4‐trisubstituted β‐carbolines through an unprecedented one‐pot triple‐orthogonal‐metal relay catalysis, and 1,3‐disubstituted 4‐hydroxy‐β‐carbolines through a one‐pot bimetallic relay catalysis from readily accessible 3‐(2‐aminophenyl)‐5‐hexenyn‐3‐ols. These strategies were elaborated to enable the synthesis of benzofuro[2,3‐ c ]pyridines, benzothieno[2,3‐ c ]pyridines, and isoquinolines, which otherwise require multistep synthesis.