Robust Organocatalytic Three-Component Approach to 1,3-Diarylallylidene Pyrazolones via Consecutive Double Condensation Reactions

The Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 16, 2024

A robust pyrrolidine-BzOH salt-catalyzed one-pot three-component reaction involving 4-unsubstituted pyrazolones, aryl/heteroarylaldehydes, and aryl methyl ketones is reported for the first time. This catalytic process fortifies an efficient method, allowing practical synthesis of a wide array synthetically useful 1,3-diarylallylidene pyrazolones in good to high yields exclusively their single geometrical isomer forms. Furthermore, this catalyst facilitates sequential double condensation under thermal conditions, thereby enabling two consecutive C═C bonds through displacement groups. Moreover, organocatalytic technique achieves 100% carbon atom economy, marking significant step forward toward sustainable synthesis.

Language: Английский

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Cu(OAc)₂/DABCO-mediated domino reaction of vinyl malononitriles with cyclic sulfamidate imines: access to 6-hydroxyaryl-2-aminonicotinonitriles

Organic & Biomolecular Chemistry, Journal Year: 2021, Volume and Issue: 20(2), P. 352 - 357

Published: Dec. 11, 2021

An efficient DABCO/Cu(OAc) 2 promoted one-pot access to pharmacologically exciting highly substituted 6-hydroxyaryl-2-aminonicotinonitriles in good high yields is reported.

Language: Английский

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Regioselective access to di- and trisubstituted pyridines via a metal-oxidant-solvent-free domino reaction involving 3-chloropropiophenones

Organic & Biomolecular Chemistry, Journal Year: 2022, Volume and Issue: 20(34), P. 6759 - 6765

Published: Jan. 1, 2022

A remarkable metal-oxidant-solvent- and base-free domino route for regioselective access to a wide range of 2,4-di- 2,3,4/6-trisubstituted pyridines including carbo- heterocyclic fused is reported. This [3C + 2C 1N] cyclization reaction occurs between 3-chloropropiophenones (3C units), enolizable acyclic/cyclic ketones (2C sources) NH4OAc as robust N source under neat conditions an open atmosphere, producing new C=C C=N-C bonds in highly chemo- manners. Interestingly, this eco-friendly method has many positive features: excellent functional group tolerance, broad substrate scope, good regioselectivities, promising yields, no-unwanted products, neutral appropriateness large-scale synthesis. Mechanism studies reveal that the situ generated β-amino ketone from 3-chloropropiophenone ammonium salt undergoes C=N bond formation with followed by intramolecular process (C=C bond), which are decisive steps pyridine

Language: Английский

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AgOTf/Et₃N Cooperative Catalysis Enabled One‐Pot Access to α‐(Indolizinylethyl)‐Substituted N‐Sulfonyl Ketimines via an Imino‐Alkyne Cyclization

Asian Journal of Organic Chemistry, Journal Year: 2022, Volume and Issue: 11(12)

Published: Nov. 1, 2022

Abstract The β‐Csp 3 −H functionalization of N‐sulfonyl ketimines with 2‐(2‐enynl)pyridines/quinolines via a cooperative Ag(I)‐/organobase‐catalyzed 5‐ endo‐dig cyclization‐addition reaction is reported. This successive C−N/C−C bond‐making provides simple and atom‐economical technique for granting diverse set 1,3‐disubstituted indolizines/pyrrolo[1,2‐ ]quinolines possessing synthetically resourceful ketimine moiety. Moreover, our designed strategy applies to broad substrates allows various functionalities. Furthermore, this has many imperative synthetic points such as mild conditions, low catalyst loading, acceptable chemical yields highly diastereoselective (up ≤93 : 7 dr). moiety indolizine was easily transmuted into the reputed classes coumarin benzofuran derivatives.

Language: Английский

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CuCl2-catalyzed N O bond cleavage of oxime esters: Approach to imidazoheterocycles and furo[3,2-c]chromenyl fused imidazoles

Tetrahedron Letters, Journal Year: 2020, Volume and Issue: 61(31), P. 152147 - 152147

Published: June 20, 2020

Language: Английский

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Swapping Copper‐Catalytic Process: Selective Access to Pyrazoles and Conjugated Ketimines from Oxime Acetates and Cyclic Sulfamidate Imines

Chemistry - An Asian Journal, Journal Year: 2022, Volume and Issue: 18(4)

Published: Dec. 30, 2022

A powerful CuCl-catalyzed sequential one-pot reaction of aryl methyl ketoxime acetates with cyclic N-sulfonyl imines followed by elimination in the presence base is reported. This hydrazine-free method conveniently makes C-C and N-N bonds via a radical cleavage N-O bond, delivering special class C3-hydroxyarylated pyrazoles good yields. Surprisingly, while employing CuI as catalyst instead CuCl, proceeds through non-radical pathway which embodies new tactic for high-yielding access to value-added conjugated N-unsubstituted ketimines. Moreover, additive-free approach sulfamidate-fused-pyrazoles was achieved successfully catalyzing addition oxidative bond-making reactions respectively. Significantly, our novel technique could convert prepared ketimines into pharmacologically recognized 6H-benzo[c]chromene frameworks.

Language: Английский

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Diastereoselective desymmetrization reactions of prochiral para-quinamines with cyclopropenes generated in situ: access to fused hydroindol-5-one scaffolds

Organic & Biomolecular Chemistry, Journal Year: 2021, Volume and Issue: 19(33), P. 7129 - 7133

Published: Jan. 1, 2021

A base-promoted diastereoselective desymmetric [3 + 2] annulation reaction of prochiral para -quinamines with 2-aroyl-1-chlorocyclopropanecarboxylates to provide a series fused-hydroindol-5-ones bearing four stereogenic centres is reported.

Language: Английский

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Organobase-catalyzed Mannich reaction of cyclic N-sulfonyl imines and 1,2-diketones: A sustainable approach to 4-(3-arylquinoxalin-2-ylmethyl)sufamidates

Tetrahedron Letters, Journal Year: 2023, Volume and Issue: 122, P. 154490 - 154490

Published: April 7, 2023

Language: Английский

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Organocatalyzed Double C(sp³)−H Alkylation of Cyclic N‐Sulfonyl Ketimines with 3‐Chloropropiophenones: Selective Access to 2,3,6‐Trisubstituted Pyridines

European Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 26(33)

Published: July 11, 2023

Abstract An efficient sequential one‐pot, two‐step pseudo‐four‐component reaction between 3/4‐methyl N ‐sulfonyl ketimines with 3‐chloropropiophenones triggered by DIPEA/NaHCO 3 as a cooperative base and subsequent aza‐cyclization using NH 4 OAc is reported. This transition‐metal‐oxidant‐free technique concocts new C−C/C=C/C=N−C bonds selectively, guaranteeing acceptable yields of 2,3,6‐trisubstituted pyridines possessing ortho ‐hydroxyaryl/benzenesulfonamide propiophenone moieties at C2 C3 positions, respectively. Interestingly, while replacing methyl‐substituents straight alkyl chains ketimines, only monoalkylation happened in situ‐generated vinyl ketones to deliver promising 3‐picoline derivatives. Moreover, the synthetic transmutation prepared pyridine derivative led several important classes pyridocoumarin, 5 H ‐chromenopyridine, di(pyridin‐3‐yl) methane

Language: Английский

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Synthesis of Poly‐Substituted Pyridines via Noble‐Metal‐Free Cycloaddition of Ketones and Imines

Chemistry - An Asian Journal, Journal Year: 2021, Volume and Issue: 16(23), P. 3905 - 3908

Published: Oct. 9, 2021

An eco-friendly and noble-metal-free formal [4+2] cycloaddition reaction was developed for the efficient synthesis of biologically interesting poly-substituted pyridines from easily available ketones imines, whereby two sequential C-C bonds are formed. The given approach features a unique synthetic strategy imines with wide substrate scope, good functional group tolerance, mild conditions operational simplicity, which represents more direct pathway to synthesize than traditional methods.

Language: Английский

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