Efficient Preparation of Polyfunctional Indoles via a Zinc Organometallic Variation of the Fischer Indole Synthesis

摘要

Functionalized organozinc reagents readily react with various aryldiazonium salts furnishing regioselectively polyfunctional indoles after heating with microwave irradiation. This new organometallic variation of the Fischer indole synthesis tolerates a wide range of functional groups and can be readily scaled up. Polyfunctional indoles are privileged structures in drug discovery and are present in numerous natural products.1 The direct synthesis of polysubstituted indole derivatives has proven to be highly challenging due to the need of harsh and acidic reaction conditions (Fischer indole synthesis) or expensive transition metal catalysis.