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
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TLDR
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.Abstract:
Catalysts comprised Pd(OAc)2 and either PCy3 or sterically hindered N-heterocyclic carbene ligands provide fast rates for a palladium-catalyzed synthesis of oxindoles by amide α-arylation. This catalyst system allowed for room-temperature reactions in some cases and reactions of aryl chlorides at 70 °C. Most important, reactions occurred in high yields under mild conditions to form the quaternary carbon in α,α-disubstituted oxindoles. The combined inter- and intramolecular reaction afforded an efficient synthetic method for formation of α-aryloxindole derivatives. Surprisingly, catalysts containing tert-butylphosphine ligands, which have been most reactive for ketone arylations, were less active than those containing PCy3. Use of new, optically active heterocyclic carbene ligands gave substantial enantioselectivity in formation of an α,α-disubstituted oxindole. In contrast, a variety of optically active phosphine ligands that were tested gave poor enantioselectivity. Mechanistic studies showed that the re...read more
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A practical large-scale preparation of 5'-bromospiro(cyclohexane-1,3-[3h]indol)-2'(1'h)-one
Bogdan Kazimierz Wilk,Arkadiy Zinoviy Rubezhov,Jean L. Helorn,Lisa R. Routel,John R. Potoski +4 more
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Microwave assisted palladium catalyzed intermolecular α-arylation of copper-amide enolate of benzazepine
TL;DR: In this article, the use of copper enolates of amides for C-C bond formation was reported, and the scope of the base, solvent, ligand, and catalysts used has also been investigated.
Journal ArticleDOI
Visible Light Promoted Polyhalomethylation of Alkenes: Alkylation and Cyclization
TL;DR: In this paper , a visible light promoted carbochloromethylation of 2-brommethyl acrylate and N-arylmethacrylamide was reported.
Journal ArticleDOI
Highly Diastereoselective Vinylogous Mukaiyama Aldol Reaction of Isatins with 2-(Trimethylsilyloxy)furans Catalyzed by Quinine
TL;DR: In this article, the Mukaiyama aldol reaction was used for the diastereoselective formation of 3-hydroxy-(5-oxo-2,5-dihydrofuran-2-yl)indolin.
Journal ArticleDOI
N-heterocyclic carbenes. IV.1synthesis of symmetrical and unsymmetrical imidazolium salts with abietane moiety†
Vladimir A. Glushkov,Vladimir A. Glushkov,K. A. Arapov,M. S. Kotelev,K. S. Rudowsky,K. Yu. Suponitsky,A. A. Gorbunov,O. A. Maiorova,Pavel A. Slepukhin +8 more
TL;DR: In this paper, a Pd-catalyzed Suzuki-Miyaura reaction was performed on methyl 12-chloromethyl-dehydroabie-tate with 1-benzyl-and 1-arylimidazoles to give unsymmetrically substituted imidazolium chlorides with abietane moiety.
References
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Journal ArticleDOI
Versatile Catalysts for the Suzuki Cross-Coupling of Arylboronic Acids with Aryl and Vinyl Halides and Triflates under Mild Conditions
TL;DR: In this paper, the authors used Pd2(dba)3/P(t-Bu)3 as a catalyst for Suzuki cross-coupling of aryl and vinyl triflates.
Journal ArticleDOI
Room-Temperature Palladium-Catalyzed Amination of Aryl Bromides and Chlorides and Extended Scope of Aromatic C−N Bond Formation with a Commercial Ligand
TL;DR: The reactions of aryl bromides with amines occurs at room temperature when using Pd(0) and P(t-Bu)(3) in a 1:1 ratio, and the reactions ofAryl chlorides occur atRoom temperature or 70 degrees C.
Journal ArticleDOI
A Convenient and General Method for Pd-Catalyzed Suzuki Cross-Couplings of Aryl Chlorides and Arylboronic Acids
Adam F. Littke,Gregory C. Fu +1 more
TL;DR: This development provides a general solution to a long-standing limitation of this extremely powerful process-the poor reactivity of inexpensive and readily accessible aryl chlorides.
Journal ArticleDOI
A Highly Active Catalyst for the Room-Temperature Amination and Suzuki Coupling of Aryl Chlorides.
TL;DR: A unique combination of steric and electronic properties appears to determine the effectiveness of phosphanyl-substituted biphenyls as ligands in palladium-catalyzed aminations and Suzuki coupling of aryl chlorides at room temperature.
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