Triorganoindium Reagents in Selective Palladium-Catalyzed CrossCoupling with lodoimidazoles: Synthesis of Neurodazine

Triorganoindium reagents (R3In, R = aryl, heteroaryl, alkynyl) react selectively under palladium catalysis with N-benzyl-2,4,5-triiodoimidazole to afford the C-2 monocoupling products. The reaction proceeds efficiently for a variety of aryl- and heteroarylindium reagents with the transfer of all three organic groups attached to the metal. The coupling products can be used in a subsequent two-fold cross-coupling to give trisubstituted imidazoles in good yields. This approach was employed to synthesize neurodazine and analogues in good yields. (Chemical Equation Presented). © 2014 American Chemical Society.