Selective Synthesis of Pyrazolo[1,2-a]pyrazolones and 2-Acylindoles via Rh(III)-Catalyzed Tunable Redox-Neutral Coupling of 1-Phenylpyrazolidinones with Alkynyl Cyclobutanols

Organic Letters, Journal Year: 2020, Volume and Issue: 22(12), P. 4697 - 4702

Published: May 28, 2020

An unprecedented divergent synthesis of pyrazolo[1,2-a]pyrazolones and 2-acylindoles via Rh(III)-catalyzed [4 + 1] or [3 2] annulation 1-phenylpyrazolidinones with alkynyl cyclobutanols through redox-neutral multiple bond activation by using −NH −OH units as directing groups is presented. Notably, different reactions were selectively achieved simply adjusting the reaction conditions. With features such simple procedures, easily accessible substrates, high regio/chemoselectivity, these methods may find wide applications in related areas.

Language: Английский

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Propargylic Alcohols as Coupling Partners in Transition‐Metal‐Catalyzed Arene C−H Activation

Advanced Synthesis & Catalysis, Journal Year: 2020, Volume and Issue: 362(23), P. 5238 - 5256

Published: Sept. 21, 2020

Abstract Transition‐metal‐catalyzed site selective arene C−H bond activation concomitant functionalization with various coupling partners gain magnificent attraction in synthetic organic chemistry as complementary to traditional transformations. Mechanistically, these approaches involve directing group assisted concerted metalation‐deprotonation (CMD), migratory insertion, and reductive elimination sequences. In this realm, diverse categories of were employed buddies. Particularly alkynes enormous attention annulating agents. These units coordinates metalcycle through π‐interaction produce annulation outcomes a straightforward manner. Very recently, propargylic alcohols appointed valuable archetypes armoury, they have shown regio‐ chemoselective insertion into primary species via hydroxy chelation. The influential regioselectivity was drawn by dual coordination metal complexes the pendent hydroxyl group. review, we focused on annulations arenes alcohols, which afford intricate cycles well complex acyclic motifs trouble‐free We categorized transformations based number atoms involved along some addition reactions. anticipate pave way towards enhanced endeavours for discovering novel reaction avenues. magnified image

Language: Английский

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Last Decade of Unconventional Methodologies for the Synthesis of Substituted Benzofurans

Molecules, Journal Year: 2020, Volume and Issue: 25(10), P. 2327 - 2327

Published: May 16, 2020

This review describes the progress of last decade on synthesis substituted benzofurans, which are useful scaffolds for numerous natural products and pharmaceuticals. In particular, new intramolecular intermolecular C-C and/or C-O bond-forming processes, with transition-metal catalysis or metal-free summarized. (1) Introduction. (2) Ring generation via cyclization. (2.1) C7a-O bond formation: (route a). (2.2) O-C2 b). (2.3) C2-C3 c). (2.4) C3-C3a d). (3) (3.1) formation a + (3.2) b (3.3) (4) Benzannulation. (5) Conclusion.

Language: Английский

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Remote C6-Enantioselective C–H Functionalization of 2,3-Disubstituted Indoles through the Dual H-Bonds and π–π Interaction Strategy Enabled by CPAs

Organic Letters, Journal Year: 2019, Volume and Issue: 21(21), P. 8662 - 8666

Published: Oct. 22, 2019

A versatile dual H-bonds and π–π interaction strategy that enables enantioselective remote C6-selective C–H functionalization of 2,3-disubstituted indoles was first reported. The N–H bond indole pivotal to achieve the C6 with excellent yield enantioselectivity. Furthermore, this methodology leads efficient construction numerous enantioenriched C6-functionalized products under mild reaction conditions employing different electrophiles. Preliminary cell proliferation investigations revealed synthesized chiral C6-substituted derivatives had potential anticancer activities.

Language: Английский

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Coupling partner-dependent unsymmetrical C–H functionalization of N-phenoxyacetamides leading to sophisticated spirocyclic scaffolds

Organic Chemistry Frontiers, Journal Year: 2022, Volume and Issue: 9(17), P. 4583 - 4590

Published: Jan. 1, 2022

In this paper, a coupling partner-dependent unsymmetrical C–H functionalization of N -phenoxyacetamides leading to the formation sophisticated spirocyclic scaffolds is presented.

Language: Английский

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Strained cycloalkanols in C–C bond formation reactions: a boon in disguise!

Organic Chemistry Frontiers, Journal Year: 2023, Volume and Issue: 10(19), P. 4941 - 4971

Published: Jan. 1, 2023

A summary of the various ring opening reactions strained and unstrained cycloalkanols is elaborated in present review. Key emphasis on reactivities pertaining to cyclopropanols, cyclobutanols higher analogues provided.

Language: Английский

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Stereoselective β–F Elimination Enabled Redox-Neutral [4 + 1] Annulation via Rh(III)-Catalyzed C–H Activation: Access to Z-Monofluoroalkenyl Dihydrobenzo[d]isoxazole Framework

Organic Letters, Journal Year: 2019, Volume and Issue: 21(13), P. 5229 - 5233

Published: June 26, 2019

An efficient and practical Rh(III)-catalyzed redox-neutral [4 + 1] annulation of N-phenoxy amides with α,α-difluoromethylene alkynes has been realized to give direct access the Z-configured monofluoroalkenyl dihydrobenzo[d]isoxazole framework broad substrate compatibility good functional group tolerance, which was further enhanced by late-stage C–H modification complex bioactive compounds. Subsequent density theory calculations revealed that stereoselective β–F elimination involving an allene species played a decisive role in determining reaction outcome such Z-selectivity.

Language: Английский

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Deconstructive Reorganization: De Novo Synthesis of Hydroxylated Benzofuran

Angewandte Chemie International Edition, Journal Year: 2020, Volume and Issue: 59(12), P. 4670 - 4677

Published: Jan. 21, 2020

An unprecedented deconstructive reorganization strategy for the de novo synthesis of hydroxylated benzofurans from kojic acid- or maltol-derived alkynes is reported. In this reaction, both benzene and furan rings were simultaneously constructed, whereas pyrone moiety acid maltol was deconstructed then reorganized into ring as a six-carbon component. Through strategy, at least one free hydroxyl group introduced in substitution-pattern tunable fashion without protection-deprotection redox adjustment. With method, large number benzofuran derivatives with different substitution-patterns have been prepared efficiently. This methodology has also shown key step collective total benzofuran-containing natural products (11 examples).

Language: Английский

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Rh(iii)-catalyzed, hydrazine-directed C–H functionalization with 1-alkynylcyclobutanols: a new strategy for 1H-indazoles

Chemical Communications, Journal Year: 2020, Volume and Issue: 56(54), P. 7415 - 7418

Published: Jan. 1, 2020

Rh(iii)-catalyzed coupling of phenylhydrazines with 1-alkynylcyclobutanols was realized through a hydrazine-directed C–H functionalization and [4+1] annulation pathway.

Language: Английский

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How achiral Brønsted acid is involved in co-catalyst model with chiral phosphoric acid for construction of quaternary carbon stereocenter

Chem Catalysis, Journal Year: 2024, Volume and Issue: 4(3), P. 100918 - 100918

Published: Feb. 7, 2024

Language: Английский

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