Exploring the Oxidative Cyclization of Substituted
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‐Aryl Enamines: Pd‐Catalyzed Formation of Indoles from Anilines
作者:Julia J. Neumann、Souvik Rakshit、Thomas Dröge、Sebastian Würtz、Frank Glorius
DOI:10.1002/chem.201100631
日期:2011.6.20
The direct Pd‐catalyzed oxidative coupling of twoCH‐bonds within N‐aryl‐enamines 1 allows the efficient formation of differently substituted indoles 2. In this cross‐dehydrogenative coupling, many different functional groups are tolerated and the starting material N‐aryl‐enamines 1 can be easily prepared in one step from commercially available anilines. In addition, the whole sequence can also be
Multisubstituted indoles were synthesized via a one-pot tandem copper-catalyzed Ullmann-type C–N bond formation/intramolecular cross-dehydrogenativecoupling process at 130 °C in DMSO. The methodology allows practical and modular assembly of indoles in good to excellent yields from readily available aryl iodides and enamines.
An Oxidant-Free Strategy for Indole Synthesis via Intramolecular C–C Bond Construction under Visible Light Irradiation: Cross-Coupling Hydrogen Evolution Reaction
We describe here an oxidant-free strategy to synthesize indoles, i.e., under visible-light irradiation (λ = 450 nm), catalytic amounts of an iridium(III) photosensitizer and cobaloxime catalyst transform various N-arylenamines exclusively into indoles. Our methodology affords indoles in good to excellent yields under mild reaction conditions and produces H2 as the only byproduct. Spectroscopic and
The construction of substituted indole skeletons is always an important concern of synthetic chemists because of its prevalent structure found in natural products and biological molecules. Here, we succeeded in preparing indoles and their derivativesfrom a wide variety of simple enamines viaradical cyclization only with catalytic amounts of an iridium(III) photosensitizer (PS) in DMSO solution under
Lewis Acid Catalyzed Indole Synthesis via Intramolecular Nucleophilic Attack of Phenyldiazoacetates to Iminium Ions
作者:Lei Zhou、Michael P. Doyle
DOI:10.1021/jo902089e
日期:2009.12.4
Lewis acids catalyze the cyclization of methyl phenyldiazoacetates with an ortho-imino group, prepared from o-aminophenylacetic acid, to give 2,3-substituted indoles in quantitative yields.