Ir-catalyzed functionalization of 2-substituted indoles at the 7-position: Nitrogen-directed aromatic borylation

…, D Holmes, RC Reichle, RE Maleczka…

Index: Paul, Sulagna; Chotana, Ghayoor A.; Holmes, Daniel; Reichle, Rebecca C.; Maleczka Jr., Robert E.; Smith III, Milton R. Journal of the American Chemical Society, 2006 , vol. 128, # 49 p. 15552 - 15553

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Citation Number: 129

Abstract

7-Functionalized indoles exist in some intriguing natural products, 3 such as asperazine, 3a chloropeptin I, 3b diazonamide A, 3c dragmacidin D, 3d and TMC-95A and B. 3e Because most of these have aryl or alkyl substituents at C7, cross-coupling reactions have been linchpins in synthetic approaches, as indicated in Scheme 1. Since C7 of indole is difficult to functionalize selectively, construction of the requisite coupling partners can be a nontrivial synthetic ...