Divergent rhodium-catalyzed electrochemical vinylic C–H annulation of acrylamides with alkynes

Nature Communications, Journal Year: 2021, Volume and Issue: 12(1)

Published: Feb. 10, 2021

α-Pyridones and α-pyrones are ubiquitous structural motifs found in natural products biologically active small molecules. Here, we report an Rh-catalyzed electrochemical vinylic C-H annulation of acrylamides with alkynes, affording cyclic good to excellent yield. Divergent syntheses α-pyridones imidates accomplished by employing N-phenyl N-tosyl as substrates, respectively. Additionally, regioselectivities achieved when using unsymmetrical alkynes. This process is environmentally benign compared traditional transition metal-catalyzed annulations because it avoids the use stoichiometric metal oxidants. DFT calculations elucidated reaction mechanism origins substituent-controlled chemoselectivity. The sequential activation alkyne insertion under rhodium catalysis leads seven-membered ring vinyl-rhodium intermediate. intermediate undergoes either classic neutral concerted reductive elimination produce α-pyridones, or ionic stepwise pathway imidates.

Language: Английский

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Recent advances in the reactions of silacyclobutanes and their applications

Organic Chemistry Frontiers, Journal Year: 2022, Volume and Issue: 9(10), P. 2840 - 2855

Published: Jan. 1, 2022

This review summarizes the growing landscape in reactions of silacyclobutanes (SCBs) by highlighting fascinating progress, deconstructing mechanistic underpinnings, and drawing insight from related ring-opening expanding SCBs.

Language: Английский

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Palladium-Catalyzed [3 + 2] Annulation of Aromatic Amides with Maleimides through Dual C–H Activation

Organic Letters, Journal Year: 2023, Volume and Issue: 25(13), P. 2190 - 2195

Published: March 26, 2023

A palladium-catalyzed [3 + 2] annulation of substituted aromatic amides with maleimides providing tricyclic heterocyclic molecules in good to moderate yields through weak carbonyl chelation is reported. The reaction proceeds via a dual C-H bond activation where the first takes place selectively at benzylic position followed by second meta afford five-membered cyclic ring. An external ligand Ac-Gly-OH has been used succeed this protocol. plausible mechanism proposed for reaction.

Language: Английский

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Ru(ii)/PEG-400 as a highly efficient and recyclable catalytic media for annulation and olefination reactions via C–H bond activation

Green Chemistry, Journal Year: 2016, Volume and Issue: 18(20), P. 5635 - 5642

Published: Jan. 1, 2016

In this report synthesis of isoquinolinones, isocoumarins, and N-methyl isoquinolinones olefination Weinreb amides by C–H bond activation using Ru(ii)/PEG-400 as green recyclable media are documented.

Language: Английский

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Rhodium(III)-Catalyzed Annulation of Pyridinones with Alkynes via Double C–H Activation: A Route to Functionalized Quinolizinones

Organic Letters, Journal Year: 2017, Volume and Issue: 19(12), P. 3083 - 3086

Published: May 30, 2017

A Rh(III)-catalyzed oxidative annulation of pyridin-2(1H)-ones with alkynes via double C–H activation to produce highly functionalized 4H-quinolizin-4-ones is disclosed. This reaction features easily available starting materials, simple manipulation, a relatively wide substrate scope, and good functional group tolerance. The application this protocol demonstrated by the synthesis known fluorescent quinolizino[3,4,5,6-ija]quinolinium salt.

Language: Английский

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Cobalt(III)-Catalyzed C–H Activation: Azo Directed Selective 1,4-Addition of Ortho C–H Bond to Maleimides

The Journal of Organic Chemistry, Journal Year: 2017, Volume and Issue: 82(13), P. 6913 - 6921

Published: May 31, 2017

Highly selective azo directed 1,4-addition of an ortho C–H bond to maleimides has been developed using Co(III) catalyst. This reaction furnishes 3-arylated succinimide derivatives in good yields with excellent selectivity. protocol exhibits a broad substrate scope and is compatible symmetrical unsymmetrical azobenzene derivatives, maleate esters. Preliminary deuterium incorporation studies have performed understand the mechanism reaction.

Language: Английский

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Cp*Rh(iii)-catalyzed C(sp³)–H alkylation of 8-methylquinolines in aqueous media

Chemical Communications, Journal Year: 2017, Volume and Issue: 53(21), P. 3006 - 3009

Published: Jan. 1, 2017

A mild and efficient approach for the cross-coupling reaction of 8-methylquinolines with a range allylic alcohols in water as solvent under rhodium(iii) catalysis is described.

Language: Английский

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Enantioselective Synthesis of C−N Axially Chiral N‐Aryloxindoles by Asymmetric Rhodium‐Catalyzed Dual C−H Activation

Angewandte Chemie, Journal Year: 2019, Volume and Issue: 131(20), P. 6804 - 6808

Published: March 20, 2019

Abstract The first enantioselective Satoh–Miura‐type reaction is reported. A variety of C−N axially chiral N‐aryloxindoles have been enantioselectively synthesized by an asymmetric rhodium‐catalyzed dual C−H activation and alkynes. High yields enantioselectivities were obtained (up to 99 % yield up ee ). To date, it also the example synthesis compounds such a strategy.

Language: Английский

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Ruthenium(II)-Catalyzed Indolo[2,1-a]isoquinolines Synthesis by Tandem C–H Allylation and Oxidative Cyclization of 2-Phenylindoles with Allyl Carbonates

Organic Letters, Journal Year: 2017, Volume and Issue: 19(9), P. 2258 - 2261

Published: April 17, 2017

A novel RuII-catalyzed tandem C–H bond activation tool has been successfully developed involving allylation and oxidative cyclization of 2-phenyl indoles with allyl carbonates. This one-pot reaction is a new way to synthesize indolo[2,1-a]isoquinoline units via simple efficient process.

Language: Английский

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Rhodium-Catalyzed sp² C–H Acetoxylation of N-Aryl Azaindoles/N-Heteroaryl Indolines

The Journal of Organic Chemistry, Journal Year: 2017, Volume and Issue: 82(23), P. 12406 - 12415

Published: Oct. 25, 2017

A silver- and copper-free rhodium-catalyzed C-H acetoxylation reaction of azaindoles has been achieved at near ambient temperature employing PIDA as a nonmetallic acetoxy source. The method is highly selective, efficient, scalable requires acetic anhydride the sole additive. scope successfully tested with wide array medicinally important heterocyclic scaffolds diverse functional group tolerance. series kinetic experiments was conducted to gain detailed insight into mechanism. methodology developed could be expanded for C7-acetoxylation indoline derivatives using pyrimidine detachable directing synthesis 7-hydroxyindole.

Language: Английский

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