title: Pd/C-Catalyzed Cyclizative Cross-Coupling of Two ortho-Alkynylanilines under Aerobic Conditions: Synthesis of 2,3'-Bisindoles.
abstract: A palladium-catalyzed cyclizative cross-coupling of two o-alkynylanilines to 2,3'-bisindoles under aerobic oxidative conditions was developed. Mechanistic studies suggested that the two catalytic cycles, namely the formation of 3-alkynylindoles 8 and their subsequent cyclization to bisindoles 5, are temporally separated. The aminopalladation of 3-alkynylindoles 8 occurred only after all the N,N-dialkyl-o-alkynylanilines were consumed. The solid support (activated charcoal) played a crucial role in the second intramolecular aminopalladation process.
authors.affiliation: Laboratory of Synthesis and Natural Products, Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne, EPFL-SB-ISIC-LSPN, BCH 5304, 1015 Lausanne (Switzerland) http://lspn.epfl.ch.
authors.forename: Bo
authors.initials: B
authors.lastname: Yao
authors.forename: Qian
authors.initials: Q
authors.lastname: Wang
authors.forename: Jieping
authors.initials: J
authors.lastname: Zhu
keywords: aerobic oxidative conditions; bisindoles; cyclizative cross-coupling; o-alkynylaniline; palladium