Journal ArticleDOI
Palladium-Catalyzed Inter- and Intramolecular α-Arylation of Amides. Application of Intramolecular Amide Arylation to the Synthesis of Oxindoles
TLDR
A palladium-catalyzed α-arylation of amides was reported in this article, where the palladium catalyst was formed in situ from Pd(dba)2 (dba = trans,trans-dibenzylidene acetone).Abstract:
2A palladium-catalyzed α-arylation of amides is reported. Intermolecular arylation of N,N-dimethylamides and lactams occurs using aryl halides, silylamide base, and a palladium catalyst. Intramolecular arylation of N-(2-halophenyl)amides occurs using alkoxide base and a palladium catalyst. The palladium catalyst was formed in situ from Pd(dba)2 (dba = trans,trans-dibenzylidene acetone) and BINAP (2,2‘-bis(diphenylphosphino)-1,1‘-binaphthalene). Although the intermolecular arylation of amides is less general than that reported previously for ketones, unfunctionalized and electron-rich aryl halides gave α-arylamides in 48−75% yield and N-methyl-α-phenylpyrrolidinone in 49% yield. These reactions provided the highest yields yet reported for regioselective amide arylations. Intramolecular amide arylation of 2-bromoanilides gave oxindoles in 52−82% yield. Mono- and disubstituted acetanilides gave 1,3-di- and 1,3,3-trisubstituted oxindoles. The use of dioxane, rather than THF, solvent was important for some of ...read more
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Journal ArticleDOI
Palladium-Catalyzed α-Arylation of Carbonyl Compounds and Nitriles
Darcy A. Culkin,John F. Hartwig +1 more
TL;DR: In this article, the palladium-catalyzed α-arylation of ketones has become a useful and general synthetic method, and the reduction of the carbon−carbon bond of the product is formed by reductive elimination from an arylpalladium enolate intermediate.
Journal ArticleDOI
Transition metal-catalyzed direct arylation of substrates with activated sp3-hybridized C-H bonds and some of their synthetic equivalents with aryl halides and pseudohalides.
Fabio Bellina,Renzo Rossi +1 more
TL;DR: New, effective, and more environmentallybenignmethodologiesfortheformation of(cyclo)alkyl-aryl bonds, which require a reduced number of synthetic operations, have emerged as valuable alternatives to the conventional cross-coupling reactions.
Journal ArticleDOI
Metal-catalyzed alpha-arylation of carbonyl and related molecules: novel trends in C-C bond formation by C-H bond functionalization.
TL;DR: This Review summarizes the developments in this area to date, with a focus on how the substrate scope has been expanded through selection of the most appropriate synthetic method, such as the careful choice of ligands, precatalysts, bases, and reaction conditions.
Journal ArticleDOI
Improved Catalysts for the Palladium-Catalyzed Synthesis of Oxindoles by Amide α-Arylation. Rate Acceleration, Use of Aryl Chloride Substrates, and a New Carbene Ligand for Asymmetric Transformations
Sunwoo Lee,John F. Hartwig +1 more
TL;DR: Mechanistic studies showed that the reaction involves rate-limiting oxidative addition of aryl halide, and use of new, optically active heterocyclic carbene ligands gave substantial enantioselectivity in formation of an alpha,alpha-disubstituted oxindole.
Journal ArticleDOI
Potassium t-butoxide alone can promote the biaryl coupling of electron-deficient nitrogen heterocycles and haloarenes.
TL;DR: Control experiments support a radical-based mechanism and suggest radical processes may be partially involved in the reported transition-metal-catalyzed arylation reactions employing t-butoxide bases and haloarenes under elevated temperatures or under microwave irradiation.
References
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Journal ArticleDOI
Equilibrium Acidities in Dimethyl Sulfoxide Solution
TL;DR: The first acidity scale to be established in a pure solvent other than water was the result of the pioneering work of Conant, Wheland, and McEwen in ether or ben~ene.
Journal ArticleDOI
Palladium-catalyzed synthesis of arylamines from aryl halides. Mechanistic studies lead to coupling in the absence of tin reagents
Janis Louie,John F. Hartwig +1 more
TL;DR: In this paper, the reaction of aryl halides with secondary amines in the presence of silylamide base and tri- o -tolyphopshine palladium complexes gives arylamine products.
Journal ArticleDOI
Palladium‐Catalyzed Regioselective Mono‐ and Diarylation Reactions of 2‐Phenylphenols and Naphthols with Aryl Halides
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Improved Catalysts for the Palladium-Catalyzed Synthesis of Oxindoles by Amide α-Arylation. Rate Acceleration, Use of Aryl Chloride Substrates, and a New Carbene Ligand for Asymmetric Transformations
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Palladium-Catalyzed α-Arylation of Carbonyl Compounds and Nitriles
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