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Heterogeneous Palladium Catalysts Applied to the Synthesis of 2‐ and 2,3‐Functionalised Indoles
Author(s) -
Djakovitch Laurent,
Dufaud Véronique,
Zaidi Rabah
Publication year - 2006
Publication title -
advanced synthesis and catalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.541
H-Index - 155
eISSN - 1615-4169
pISSN - 1615-4150
DOI - 10.1002/adsc.200505283
Subject(s) - chemistry , catalysis , palladium , yield (engineering) , aryl , indole test , solvent , homogeneous catalysis , heterogeneous catalysis , reactivity (psychology) , coupling reaction , organic chemistry , homogeneous , combinatorial chemistry , medicinal chemistry , medicine , materials science , alkyl , alternative medicine , physics , pathology , metallurgy , thermodynamics
Abstract Heterogeneous palladium catalysts ([Pd(NH 3 ) 4 ] 2+ /NaY and [Pd]/SBA‐15) were applied to the synthesis of 2‐functionalised indoles, giving generally high conversions and selectivities (>89% yield) using only 1 mol % [Pd]‐catalyst under standard reaction conditions (polar solvent, 80 °C). For the synthesis of 2,3‐functionalised indoles by cross‐coupling arylation, the [Pd]/SBA‐15 catalyst was found to be particularly interesting, producing the expected compound with =35% yield after 12 days of reaction, which is comparable to the homogeneous catalyst, Pd(OAc) 2 (=48% yield). In the course of the study, the dual reactivity of the indole nucleus was demonstrated: aryl bromides gave clean CC coupling while aryl iodides led to a clean CN coupling.