Iron (III) Trichloride-Catalyzed One-Pot Three-Component Coupling of Indoles and Sodium Nitrite: A Convenient Synthesis of 2,3'-Bi(3H-indol)-3-one oximes

A simple, convenient and efficient three-component coupling (TCC) reaction toward a variety of (E)-2,3'-bi(3H-indol)-3-one oxime derivatives has been developed. This transformation proceeds via an iron (III)-catalyzed tandem coupling reaction between indoles and sodium nitrite. This methodology provides an alternative approach for easy access of (E)-2,3'-bi(3H-indol)-3-one oximes in good to excellent yields at room temperature.