C–H bond functionalization by high-valent cobalt catalysis: current progress, challenges and future perspectives

Chemical Communications, Journal Year: 2021, Volume and Issue: 57(83), P. 10827 - 10841

Published: Jan. 1, 2021

Over the last decade, high-valent cobalt catalysis has earned a place in spotlight as valuable tool for C-H activation and functionalization. Since discovery of its unique reactivity, more attention been directed towards utilization an alternative to noble metal catalysts. In particular, Cp*Co(III) complexes, well simple Co(II) Co(III) salts combination with bidentate chelation assistance, have extensively used development novel transformations. this review, we demonstrated existing trends functionalization methodology using highlighted main challenges overcome, perspective directions, which need be further developed future.

Language: Английский

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Cobalt-Catalyzed Domino Transformations via Enantioselective C–H Activation/Nucleophilic [3 + 2] Annulation toward Chiral Bridged Bicycles

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(22), P. 15576 - 15586

Published: May 16, 2024

Selective synthesis of chiral bridged (hetero)bicyclic scaffolds via asymmetric C–H activation constitutes substantial challenges due to the multiple reactivities strained bicyclic structures. Herein, we develop domino transformations through an unprecedented cobalt-catalyzed enantioselective activation/nucleophilic [3 + 2] annulation with symmetrical alkenes. The methods offer straightforward access a wide range molecules bearing [2.2.1]-bridged cores four and five consecutive stereocenters in single step. Two elaborate salicyloxazoline (Salox) ligands were synthesized based on rational design mechanistic understanding. well-defined pockets generated from coordination around trivalent cobalt catalyst direct orientation alkenes, leading excellent enantioselectivity.

Language: Английский

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Additive-Controlled Divergent Synthesis of Tetrasubstituted 1,3-Enynes and Alkynylated 3H-Pyrrolo[1,2-a]indol-3-ones via Rhodium Catalysis

Organic Letters, Journal Year: 2021, Volume and Issue: 23(3), P. 727 - 733

Published: Jan. 8, 2021

Herein, we report the additive-controlled divergent synthesis of tetrasubstituted 1,3-enynes and alkynylated 3H-pyrrolo[1,2-a]indol-3-ones through rhodium-catalyzed C-H alkenylation/DG migration [3+2] annulation, respectively. This protocol features rare directing group in 1,3-diyne-involved activation, excellent regio- stereoselectivity, monofunctionalization over difunctionalization, broad substrate scope, moderate to high yields, good functional compatibility, mild redox-neutral conditions.

Language: 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, Journal Year: 2022, Volume and Issue: 13(9), P. 2692 - 2700

Published: Jan. 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.

Language: 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, Journal Year: 2022, Volume and Issue: 24(18), P. 3395 - 3400

Published: May 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.

Language: Английский

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Cp*Co(III)-Catalyzed Regioselective [4 + 2]-Annulation of N-Chlorobenzamides with Vinyl Acetate/Vinyl Ketones

The Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 88(3), P. 1578 - 1589

Published: Jan. 21, 2023

An efficient and straightforward strategy for the synthesis of isoquinolones through [4 + 2]-annulation N-chlorobenzamides with vinyl acetate in presence CoCp*(III) catalyst a regioselective manner is described. Furthermore, annulation reaction was diversified by using ketones. By utilizing this strategy, biologically valuable isoquinolone derivatives were prepared good yields. Subsequently, further transformed into 1-chloroisoquinolines POCl3. mechanistic investigations such as deuterium labeling study competition experiment performed to support proposed mechanism.

Language: Английский

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Cobalt catalyzed alkenylation/annulation reactions of alkynes via C–H activation: A review

Tetrahedron, Journal Year: 2023, Volume and Issue: 132, P. 133248 - 133248

Published: Jan. 9, 2023

Language: Английский

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Traceless Directing Groups in Sustainable Metal-Catalyzed C–H Activation

Catalysts, Journal Year: 2021, Volume and Issue: 11(5), P. 554 - 554

Published: April 27, 2021

Sustainable transformations towards the production of valuable chemicals constantly attract interest, both in terms academic and applied research. C–H activation has long been scrutinized this regard, given that it offers a straightforward pathway to prepare compounds great significance. In context, directing groups (DG) have paved way for chemical had not achievable using traditional reactions. Few steps, high yields, selectivity inert substrates are some invaluable assets directed catalysis. Additionally, employment traceless (TDG) greatly improves simplifies strategy, enabling realization multi-step reactions one-pot, cascade procedures. Cheap, abundant, readily available transition metal salts complexes can catalyze plethora employing TDGs, usually under low catalyst loadings—rarely stoichiometric amounts, leading greater atom economy milder conditions with increased yields step-economy. This review article summarizes all work done on TDG-assisted catalysis manganese, iron, cobalt, nickel, or copper catalysts, discusses structure-activity relationships observed, by presenting catalytic pathways range reported thus far.

Language: 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, Journal Year: 2022, Volume and Issue: 87(6), P. 4134 - 4153

Published: March 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.

Language: Английский

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Hydrazone-oxime Selectively Directed Redox-Neutral [4 + 2] Annulations Cascade with Alkynes and Iodonium Ylides to Build 1,1′-Biisoquinoline Mono-N-oxides

Organic Letters, Journal Year: 2023, Volume and Issue: 25(15), P. 2616 - 2621

Published: April 12, 2023

Selective C-H activation of a molecule containing multiple directing groups is an important but challenging issue in organic chemistry. Herein, combined group (hydrazone-oxime) selectively directed [4 + 2] annulation cascade to synthesize novel 1,1'-biisoquinoline mono-N-oxides has been developed. Owing the subtle differences electronic properties between hydrazone and oxime, first with alkynes preferentially occurs at side form 1-oximido isoquinolines, which then undergoes second iodonium ylides oxime side. The two annulations work smoothly under redox-neutral conditions can be performed one pot, without utilization stoichiometric external oxidants. Moreover, ESI-MS DFT calculations have conducted corroborate reaction mechanism. Such biisoquinoline skeletons pave way for future research prospects synthetic value.

Language: Английский

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