Organocatalyzed Double C(sp3)−H Alkylation of Cyclic N‐Sulfonyl Ketimines with 3‐Chloropropiophenones: Selective Access to 2,3,6‐Trisubstituted Pyridines DOI
Ashvani K. Patel, Sampak Samanta

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

Base-Promoted and Copper(I)-Catalyzed Tandem Cyclization-C(sp2)-N Coupling of Vinyl Malononitriles with Ortho-Nitrochalcones: Access to Acridones and their Fused Derivatives DOI

Raju Lal Dhakar,

S Banuprakash Goud,

Sampak Samanta

et al.

The Journal of Organic Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 28, 2025

An efficient Cs2CO3-promoted and copper(I)-catalyzed double cyclization of ortho-nitrochalcones with vinyl malononitriles for the de novo access to a variety tri- tetra-substituted acridones their fused derivatives value-added CN group has been developed first time. This one-pot operation proceeds through Michael-cyclization-aromatization, followed by regioselective ipso-amination via nucleophilic aromatic substitution (SNAr) reaction, resulting in two C═C bonds C-N bond acridone ring synthesis. economic strategy based on 100% carbon atoms ensures successive formation rings operation, good high yields, wide range substrates, tolerance functionalities. In addition, were converted into several acridines, highlighting synthetic versatility usefulness prepared derivatives.

Language: Английский

Citations

0
One-pot π-extension approach of iminoindoles-to-α-carbolines as blue-light emitters using the cooperative basic system DOI

Rajni Lodhi,

S Banuprakash Goud,

Sampak Samanta

et al.

New Journal of Chemistry, Journal Year: 2024, Volume and Issue: 48(32), P. 14163 - 14169

Published: Jan. 1, 2024

Efficient access to α-carbolines was achieved via a domino reaction between iminoindoles and arylidene malononitriles using DABCO/NaHCO 3 as cooperative basic system. The synthesized scaffolds display blue emissions with good quantum yields.

Language: Английский

Citations

2
Regioselective access to di- and trisubstituted pyridines via a metal-oxidant-solvent-free domino reaction involving 3-chloropropiophenones DOI
Ashvani K. Patel,

Shikha Singh Rathor,

Sampak Samanta

et al.

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

Citations

7
AgOTf/Et3N Cooperative Catalysis Enabled One‐Pot Access to α‐(Indolizinylethyl)‐Substituted N‐Sulfonyl Ketimines via an Imino‐Alkyne Cyclization DOI

Rajni Lodhi,

Ashvani K. Patel, Sampak Samanta

et al.

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

Citations

7
Copper(I)‐Photocatalyzed Diastereoselective Aziridination of N‐Sulfonyl Imines with Vinyl Azides: Application to Benzo[f][1,2,3]oxathiazepines Dioxides and Fused Isoxazolines DOI

S Banuprakash Goud,

Raju Lal Dhakar,

Sampak Samanta

et al.

Chemistry - An Asian Journal, Journal Year: 2023, Volume and Issue: 19(2)

Published: Nov. 29, 2023

Abstract An in situ generated photoactive copper(I)‐complex‐catalyzed aziridination reaction of cyclic N‐sulfonyl imines with α‐aryl‐substituted vinyl azides irradiated by blue‐LEDs light is reported for the first time. This novel SET process represents a mild, sustainable, and pragmatic method accessing synthetically resourceful sulfamidate‐fused aziridines acceptable chemical yields excellent diastereoselectivities. Delightedly, pharmacologically attractive benzo[ f ][1,2,3]oxathiazepine dioxides fused isoxazoline frameworks were achieved through our newly developed metal‐free based ring‐expansion techniques, highlighting synthetic value accessed aziridines. Finally, possible mechanism [2+1] aza‐cyclization was presented on conduction series control experiments.

Language: Английский

Citations

4
Acidic tributyl phosphonium-based ionic liquid: an efficient catalyst for preparation of diverse pyridine systems via a cooperative vinylogous anomeric-based oxidation DOI Creative Commons

Sepideh Jalali-Mola,

Morteza Torabi, Meysam Yarie

et al.

RSC Advances, Journal Year: 2022, Volume and Issue: 12(53), P. 34730 - 34739

Published: Jan. 1, 2022

Experimental procedure for the synthesis of triaryl pyridines, indolyl pyridines and nicotinonitriles.

Language: Английский

Citations

6
Swapping Copper‐Catalytic Process: Selective Access to Pyrazoles and Conjugated Ketimines from Oxime Acetates and Cyclic Sulfamidate Imines DOI

Meher Prakash,

Sajal Halder, Soumitra Guin

et al.

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

Citations

5
Organobase-catalyzed Mannich reaction of cyclic N-sulfonyl imines and 1,2-diketones: A sustainable approach to 4-(3-arylquinoxalin-2-ylmethyl)sufamidates DOI

Poonam Rani,

Meher Prakash,

Sampak Samanta

et al.

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

Published: April 7, 2023

Language: Английский

Citations

2
Organocatalyzed Modular Synthesis of Polycyclic Dihydropyridines and Pyridines through Sulfamate Linchpin DOI

Vinod Bhajammanavar,

Popuri Sureshbabu,

Mallu Kesava Reddy

et al.

Chemistry - An Asian Journal, Journal Year: 2022, Volume and Issue: 17(15)

Published: May 16, 2022

The cascade annulation between alkylidene malononitriles and cyclic sulfamidate imines has been controlled by leveraging the sulfamate functionality under organocatalysis, which allows selective access to polycyclic densely functionalized dihydropyridines pyridines in high yields. protocol is scalable shows broad substrate scope. products were also engaged preparation of tetracyclic pyridopyrimidines, showcasing synthetic versatility.

Language: Английский

Citations

3
Organocatalyzed Double C(sp3)−H Alkylation of Cyclic N‐Sulfonyl Ketimines with 3‐Chloropropiophenones: Selective Access to 2,3,6‐Trisubstituted Pyridines DOI
Ashvani K. Patel, Sampak Samanta

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

Citations

1