Acetoxy Group-Directed Regioselective C2 Alkenylation of Indoles via Pd–Ag Bimetallic Catalysis

The Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 88(20), P. 14423 - 14434

Published: Oct. 5, 2023

Regioselective C–H functionalizations of indoles reported to date with directing groups at C3 mainly rely on functional that are linked the indole via C–C bonds. However, core by C–X linkages also attractive due possibility further modifications bond. Herein, we report a 3-acetoxy group for regioselective C2 alkenylation activation-based, cross-dehydrogenative, oxidative Heck-type reaction. The reaction is catalyzed Pd(II) and Ag(I) stoichiometric Cu(II) as oxidant provides 2-alkenylated in yields 52–84%. conditions compatible several different positions well N-protecting or free NH core. With respect alkene coupling partners, reactions successful acrylates, vinyl sulfates, phosphates. Specifically designed experiments, density theory (DFT) computational studies, reveal heterodinuclear [Pd(μ-OAc)3Ag] bimetallic species actual catalyst responsible alkenylation. A mechanistic path involving this catalytic was found be favorable over other possible pathways explaining observed regioselectivity through DFT studies.

Language: Английский

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Non-Noble-Metal Mono and Bimetallic Composites for Efficient Electrocatalysis of Phosphine Oxide and Acetylene C-H/P-H Coupling under Mild Conditions

International Journal of Molecular Sciences, Journal Year: 2023, Volume and Issue: 24(1), P. 765 - 765

Published: Jan. 1, 2023

The present work describes an efficient reaction of electrochemical phosphorylation phenylacetylene controlled by the composition catalytic nanoparticles based on non-noble-metals. sought-after products are produced via simple synthetic protocol room temperature, atom-economical reactions, and silica (SNs) loaded one or two d-metal ions as nanocatalysts. redox properties SNs can be tuned with a range parameters, such compositions bimetallic systems, their preparation method, morphology. Monometallic give phosphorylated acetylene retention triple bond, bis-phosphorylation product. This is first example phosphine oxide C-H/P-H coupling regenerable recyclable catalyst.

Language: Английский

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Ligand Combination Approach in Pd‐Catalyzed Direct C−H Arylation of Benzothiazole and Benzoxazole

European Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 27(2)

Published: Nov. 3, 2023

Abstract The use of ligand combination approach in the Pd catalyzed direct C−H arylation benzothiazole and benzoxazole is demonstrated. two ligands phenanthroline monohydrate (Phen.H 2 O) triphenylphosphine (PPh 3 ) with Pd‐catalyst have offered best catalytic properties bond reactions than either employed separately reactions. This protocol exhibits a wide substrate scope affording C2 arylated derivatives excellent yields. Mechanistic studies including kinetic isotope effect (KIE), H/D exchange competition experiments show that activation very facile under reaction conditions. Furthermore, different mechanistic pathways originated from catalytically active species such as Pd(η ‐dba)L (dba=dibenzylidene acetone) Pd(PPh were investigated using computational methods. results suggest generation (dba) endoergic process Phen can initiate this step. On other hand, presence PPh could be crucial for oxidative addition aryl halides which rate‐determining step reaction.

Language: Английский

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An Efficient Copper-Mediated Route for the Synthesis of 2-Substituted Benzothiazoles from Dithioesters and Investigation of Their Antibacterial Activities

Synthesis, Journal Year: 2023, Volume and Issue: 56(03), P. 469 - 481

Published: Oct. 17, 2023

Abstract An efficient one-pot synthesis of 2-aryl/2-aroylbenzothiazoles through copper-mediated condensation 2-chloroanilines with dithioesters has been developed. The method provides good isolated yields and exhibits broad functional group tolerance, accommodating both electron-donating electron-withdrawing groups on the substrates. A series synthesized compounds was evaluated for their antibacterial activity against Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella paratyphi. Among series, three exhibited a significant inhibitory effect tested pathogens, one also demonstrating potential as an effective compound in agar well diffusion assay broth microdilution assay. Additionally, displayed strong effects biofilm formation pathogens crystal violet MTT at concentration 10 mM. These findings highlight promising antimicrobial antibiofilm properties these compounds, indicating further investigation therapeutic agents pathogens.

Language: Английский

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