Rhodium‐Catalyzed Atroposelective Access to Axially Chiral Olefins via C−H Bond Activation and Directing Group Migration

Angewandte Chemie International Edition, Год журнала: 2021, Номер 61(1)

Опубликована: Окт. 22, 2021

Axially chiral open-chain olefins represent an underexplored class of platform. In this report, two classes tetrasubstituted axially acyclic have been accessed in excellent enantioselectivity and regioselectivity via C-H activation (hetero)arenes assisted by a migratable directing group en route to coupling with sterically hindered alkynes. The indoles bearing N-aminocarbonyl afforded C-N acrylamides the assistance racemic zinc carboxylate additive. DFT studies suggest β-nitrogen elimination-reinsertion pathway for migration. Meanwhile, employment N-phenoxycarboxamide delivered C-C enamides migration oxidizing group. Experiments that both cases (hetero)arene substrate adopts well-defined orientation during activation, which turn determines disposition alkyne migratory insertion. Synthetic applications representative are demonstrated.

Язык: Английский

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Transition metal-catalyzed C–H functionalizations of indoles

New Journal of Chemistry, Год журнала: 2021, Номер 45(31), С. 13692 - 13746

Опубликована: Янв. 1, 2021

This review summarises a wide range of transformations on the indole skeleton, including arylation, alkenylation, alkynylation, acylation, nitration, borylation, and amidation, using transition-metal catalyzed C–H functionalization as key step.

Язык: Английский

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E/Z Photoisomerization of Olefins as an Emergent Strategy for the Control of Stereodivergence in Catalysis

Advanced Synthesis & Catalysis, Год журнала: 2022, Номер 364(8), С. 1348 - 1370

Опубликована: Март 5, 2022

Abstract The stereoselective photoisomerization of olefins via Energy Transfer (E n T) sensitization bears significant potential in the context rational design catalytic stereodivergent methodologies. Whereas approaches for controlling access to E‐ and Z ‐ isomers depend highly on nature catalyst – therefore are not easily implemented as a general strategy E T catalysis has emerged recent years an increasingly powerful tool olefin geometry control nearly perfect step‐economic fashion. Moreover, this approach presents both high functional group tolerance and, most notably, demonstrated ample multicatalytic compatibility. This feature enabled development tandem strategies, which focus Review. magnified image

Язык: Английский

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Rh-Catalyzed [4 + 2] Annulation with a Removable Monodentate Structure toward Iminopyranes and Pyranones by C–H Annulation

Organic Letters, Год журнала: 2022, Номер 24(16), С. 3003 - 3008

Опубликована: Апрель 20, 2022

The Rh-catalyzed reactions of N-pyridinyl enaminones with internal alkynes leading to the synthesis iminopyranes via a key C–H bond activation and subsequent tautomeric O–H cleavage are reported. Moreover, pyridine ring in amino group acts as an auxiliary monodentate site for this annulation can be easily removed by simple hydrolysis afford pyranones.

Язык: Английский

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Rh(iii)-catalyzed C–H activation/annulation of N-carbamoylindoles with CF₃-imidoyl sulfoxonium ylides for the divergent synthesis of trifluoromethyl-substituted (dihydro)pyrimidoindolones

Organic Chemistry Frontiers, Год журнала: 2023, Номер 10(15), С. 3843 - 3848

Опубликована: Янв. 1, 2023

We have developed a Rh( iii )-catalyzed C–H activation/chemodivergent annulation of N -carbamoylindoles with TFISYs, allowing facile access to variety trifluoromethyl-substituted (dihydro)pyrimidoindolones high efficiency. Solvents play critical role in the selectivity reaction.

Язык: Английский

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Cobalt(III)-Catalyzed Regioselective C6 Olefination of 2-Pyridones Using Alkynes: Olefination/Directing Group Migration and Olefination

Organic Letters, Год журнала: 2021, Номер 23(12), С. 4624 - 4629

Опубликована: Июнь 9, 2021

Co(III)-catalyzed highly regio- and stereoselective direct C6 olefination of 2-pyridones with alkynes has been developed the assistance chelation. Upon variation reaction conditions, react well diaryl via a olefination/directing group migration pathway to give tetrasubstituted 6-vinyl-2-pyridones, but C6-H terminal works effectively afford only C6-olefinated 2-pyridones. A judicious choice solvent an additive is crucial for catalysis. The protocols feature 100% atom economy, excellent site selectivity, high stereoselectivity, ample substrate scope, good compatibility functional groups. Synthetic applications are demonstrated, experimental studies density theory calculations conducted gain mechanistic insight into two transformations.

Язык: Английский

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Rh(III)-Catalyzed Divergent Synthesis of Alkynylated Imidazo[1,5-a]indoles and α,α-Difluoromethylene Tetrasubstituted Alkenes

Organic Letters, Год журнала: 2021, Номер 23(15), С. 5766 - 5771

Опубликована: Июль 19, 2021

Herein, we report the divergent synthesis of alkynylated imidazo[1,5-a]indoles and α,α-difluoromethylene tetrasubstituted alkenes through Rh(III)-catalyzed [4 + 1] annulation/alkyne moiety migration C–H alkenylation/DG migration, respectively. This protocol features tunable product selectivity, excellent chemo-, regio-, stereoselectivity, broad substrate scope, moderate to high yields, good tolerance functional groups, mild redox-neutral conditions.

Язык: Английский

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Palladium-catalyzed selective C–C bond cleavage and stereoselective alkenylation between cyclopropanol and 1,3-diyne: one-step synthesis of diverse conjugated enynes

Chemical Science, Год журнала: 2022, Номер 13(9), С. 2692 - 2700

Опубликована: Янв. 1, 2022

Palladium-catalyzed tandem activation and functionalization of readily accessible cyclopropanols have been demonstrated to access valuable conjugated enynes from 1,3-diynes with high stereo-selectivity.

Язык: Английский

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Synthesis of Indenone Derivatives by Rh(III)-Catalyzed C–H Functionalization of Sulfoxonium Ylides with 1,3-Diynes

Organic Letters, Год журнала: 2022, Номер 24(18), С. 3395 - 3400

Опубликована: Май 5, 2022

The transition-metal-catalyzed C-H functionalization of sulfoxonium ylides with alkynes formally participates in [4 + 2] annulations to deliver the naphthol scaffolds. In contrast, herein we disclose first Rh(III)-catalyzed activation, followed by redox-neutral [3 annulation 1,3-diynes, which delivers alkynated indenone derivatives. This protocol features a good functional group tolerance, broad substrate scope, moderate excellent yields, and mild reaction conditions. mechanism was supported through ESI-HRMS characterizing key intermediates catalytic cycle.

Язык: Английский

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Cobalt(III)-Catalyzed Chemo- and Regioselective [4 + 2]-Annulation of Aromatic Sulfoxonium Ylides with 1,3-Diynes

The Journal of Organic Chemistry, Год журнала: 2022, Номер 87(6), С. 4134 - 4153

Опубликована: Март 4, 2022

Air-stable, highly abundant, and cost-effective Co(III)-catalyzed redox-neutral [4 + 2]-annulation of aromatic sulfoxonium ylides with 1,3-diynes providing useful substituted 1-naphthol derivatives in a regioselective manner is described. Further, the prepared 1-naphthols having internal alkyne were converted into polycarbocyclic molecules spiro-dienone good-to-excellent yields. A possible reaction mechanism involving ortho C–H activation as key step was proposed supported by deuterium labeling kinetic isotope studies.

Язык: Английский

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