Bis-Suzuki reactions of 2,3-dihaloindoles. A convenient synthesis of 2,3-diarylindoles

A convenient, one-pot synthesis of 2,3-diarylindoles 4 is described via a bis-Suzuki palladium-catalyzed cross coupling of 2,3-dihalo-1-(phenylsulfonyl)indoles 1 with arylboronic acids 2, followed by cleavage of the N-protecting group to give 4. The anti-inflammatory drug indoxole (4c) is prepared in high yield. (C) 2000 Elsevier Science Ltd. All rights reserved.