2,3-Disubstituted indoles bearing 2-hydroxyphenyl moieties at their C3 positions were synthesized from readily available 2-chlorophenols and alkynylanilines via aminopalladation/reductive elimination using Pd–dihydroxyterphenylphosphine catalyst. The catalyst accelerates the introduction of the 2-hydroxyphenyl group at the C3 position of the indole.
Electrophilic indole? Indoles, which are typically nucleophilic, can be made electrophilic throughgoldcatalysis. By using an ortho‐azido group to deliver a nitrene intramolecularly, an arylalkyne is converted into a gold carbene intermediate containing an indole skeleton that is highly electrophilic at the 3‐position. A range of functionalized indoles is readily accessed by utilizing this strategy
Regioselective Pd-catalyzed indolization of 2-bromoanilines with internal alkynes using phosphine-free ligands
作者:Xin Cui、Juan Li、Yao Fu、Lei Liu、Qing-Xiang Guo
DOI:10.1016/j.tetlet.2008.03.112
日期:2008.5
The possibility of using phosphine-free ligands to promote Pd-catalyzed indolization of 2-bromoanilines with internal alkynes was examined for the first time. Phenylurea was found to be the optimal ligand, which could mediate the synthesis of 2,3 -disubstituted indoles in good yields (ca. 60-85%) with high regioselectivity. (C) 2008 Elsevier Ltd. All rights reserved.