Palladium-Catalyzed C–H Arylation of Indoles at the C7 Position

Journal of the American Chemical Society, Год журнала: 2015, Номер 138(2), С. 495 - 498

Опубликована: Дек. 28, 2015

In the past decade, direct C-H arylation of indoles has been developed with high selectivity at C2 and C3 positions via transition-metal-catalyzed cross-coupling reactions. Here we show that activation can be directed to C7 position in Pd-catalyzed coupling arylboronic acids. The key this regioselectivity is appropriate choice a phosphinoyl directing group pyridine-type ligand presence Pd(OAc)2 catalyst. This previously elusive transformation should provide insight for design other cross-couplings as well.

Язык: Английский

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Cross‐Coupling of α‐Carbonyl Sulfoxonium Ylides with C−H Bonds

Angewandte Chemie International Edition, Год журнала: 2017, Номер 56(42), С. 13117 - 13121

Опубликована: Авг. 29, 2017

Abstract The functionalization of carbon–hydrogen bonds in non‐nucleophilic substrates using α‐carbonyl sulfoxonium ylides has not been so far investigated, despite the potential safety advantages that such reagents would provide over either diazo compounds or their situ precursors. Described herein are cross‐coupling reactions with C(sp 2 )−H arenes and heteroarenes presence a rhodium catalyst. reaction proceeds by succession C−H activation, migratory insertion ylide into carbon–metal bond, protodemetalation, last step being turnover‐limiting. method is applied to synthesis benz[c]acridines when allied an iridium‐catalyzed dehydrative cyclization.

Язык: Английский

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Oxazolinyl-Assisted C–H Amidation by Cobalt(III) Catalysis

ACS Catalysis, Год журнала: 2015, Номер 6(2), С. 793 - 797

Опубликована: Дек. 22, 2015

Cobalt-catalyzed C–H activation by means of oxazolinyl assistance set the stage for versatile direct amidations with ample substrate scope. Thus, a high-valent cobalt(III) catalyst enabled excellent levels positional and chemo-selectivities. Mechanistic studies provided strong support kinetically relevant functionalization.

Язык: Английский

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C–H functionalization by high-valent Cp*Co(iii) catalysis

Chemical Communications, Год журнала: 2017, Номер 53(22), С. 3165 - 3180

Опубликована: Янв. 1, 2017

Significant progress has been accomplished in directed C–H functionalization through the use of earth-abundant and inexpensive first-row transition metals.

Язык: Английский

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Diazo Compounds: Versatile Synthons for the Synthesis of Nitrogen Heterocycles via Transition Metal‐Catalyzed Cascade C–H Activation/Carbene Insertion/Annulation Reactions

Advanced Synthesis & Catalysis, Год журнала: 2018, Номер 361(5), С. 919 - 944

Опубликована: Ноя. 27, 2018

Abstract This review covers some unique diazo compounds, the coupling partners to access various versatile functionalized nitrogen heterocycles, such as indoles, indolines, isoquinolines, isoquinolones, and so on. Different transition metals (such Rh, Pd, Ru, Ir, Cu, Co) are involved in these transformations, which involve consecutive processes: metal‐catalyzed cascade C–H activation/carbene insertion/intramolecular annulation. magnified image

Язык: Английский

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Cu-Catalyzed Direct C6-Arylation of Indoles

Journal of the American Chemical Society, Год журнала: 2016, Номер 138(28), С. 8734 - 8737

Опубликована: Июнь 30, 2016

The first example of direct and site-selective arylation indoles at the C6 position has been reported. key to this high regioselectivity is appropriate choice N–P(O)tBu2 directing group use diaryliodonium triflate salts as coupling partners in presence catalytic CuO. protocol distinguished by mild reaction system that avoids ligand additives, exhibiting wide scope indole arene components without compromising its efficiency scalability, thus representing a significant advancement implementation regioselective indoles.

Язык: Английский

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Enantioselective Cobalt(III)‐Catalyzed C−H Activation Enabled by Chiral Carboxylic Acid Cooperation

Angewandte Chemie International Edition, Год журнала: 2018, Номер 57(47), С. 15425 - 15429

Опубликована: Окт. 6, 2018

The enantioselective cobalt(III)-catalyzed C-H alkylation was achieved through the design of a novel chiral acid. activation characterized by high position-, regio- and enantio-control under exceedingly mild reaction conditions. Thereby, robust cooperative cobalt(III) catalysis proved tolerant valuable electrophilic functional groups, including hydroxyl, bromo, iodo substituents. Mechanistic studies revealed considerable additive effect on kinetics negative non-linear-effect.

Язык: Английский

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Cobalt‐Catalyzed C−H Thiolation through Dehydrogenative Cross‐Coupling

Angewandte Chemie International Edition, Год журнала: 2016, Номер 55(37), С. 11287 - 11291

Опубликована: Июль 20, 2016

Abstract A cobalt‐catalyzed dehydrogenative cross‐coupling of thiols and indoles is reported. Using a cooperative reaction system, new mode action for the C−heteroatom bond formation was found. The directed C−H activation catalysis overrides an undirected thiolation indole in 3‐position that occurs absence cobalt. Mechanistic studies indicate sequence activation, thiolate transfer, reductive elimination.

Язык: Английский

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Cobalt(III)‐Catalyzed Dehydrative [4+2] Annulation of Oxime with Alkyne by CH and NOH Activation

Chemistry - A European Journal, Год журнала: 2015, Номер 21(44), С. 15529 - 15533

Опубликована: Сен. 25, 2015

Efficient, scalable cobalt-catalyzed redox-neutral [4+2] annulation of readily available oximes and alkyne is reported. The developed synthetic methodology widely applicable tolerates various functional groups including heterocycles. A stable Cp*Co(III) neutral complex employed as the catalyst for this reaction, which progresses smoothly by way a reversible cyclometallation without any external oxidizing agent, produces only water side product.

Язык: Английский

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Cobalt‐Catalyzed Oxidative Annulation of Nitrogen‐Containing Arenes with Alkynes: An Atom‐Economical Route to Heterocyclic Quaternary Ammonium Salts

Angewandte Chemie International Edition, Год журнала: 2016, Номер 55(5), С. 1844 - 1848

Опубликована: Янв. 11, 2016

Abstract Four cobalt‐catalyzed oxidative annulation reactions of nitrogen‐containing arenes with alkynes proceeds by C−H activation, thus leading to biologically useful quaternary ammonium salts, including pyridoisoquinolinium, cinnolinium, isoquinolinium, and quinolizinium in high yields. The results are comparable those catalyzed rhodium ruthenium complexes. transformation the salts into various N‐heterocycles has also been demonstrated.

Язык: Английский

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