Synthesis of Polyfunctional Indazoles via Novel Rearrangement of Isatin Derivatives

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

Published: Feb. 3, 2025

Abstract In this work we present a new method for indazole synthesis through the unexpected rearrangement of various 7‐nitroisatins during reaction with hydrazine hydrate. The pyrazole cycle is formed via direct metal‐free C−H amination. We demonstrate limitations discovered approach and several accessible methods functionalization compounds to obtain novel derivatives.

Language: Английский

---

NIS mediated dehydrogenative-cyclocondensation in aqueous medium towards the synthesis of 2-arylimidazo[1,2-a]pyridines and their 3-formylated derivatives

Tetrahedron, Journal Year: 2022, Volume and Issue: 112, P. 132715 - 132715

Published: March 19, 2022

Language: Английский

---

Phospha-Michael addition of biphenylphosphine oxide to chalcones and α,β-unsaturated esters using the organocatalyst 1,1-diaminobenzalazine

Tetrahedron Letters, Journal Year: 2023, Volume and Issue: 122, P. 154505 - 154505

Published: April 21, 2023

Language: Английский

---

1,1-Diaminoazines as organocatalysts in phospha-Michael addition reactions

Chemical Communications, Journal Year: 2021, Volume and Issue: 57(88), P. 11717 - 11720

Published: Jan. 1, 2021

1,1-Diaminoazines can act as effective organocatalysts for the formation of phosphorus-carbon bonds between biphenylphosphine oxide and an activated alkene (Michael acceptor). These catalysts provide P-C adducts at a faster rate with relatively better yields in comparison to employed earlier. The notable advantage is that 1,1-diaminoazines catalyse reaction even aqueous medium very good yields. Organocatalysis using was also successfully carried out dimethylphosphite benzylidenemalononitrile under multicomponent conditions.

Language: Английский

---

Methods for the synthesis of 1H-pyrazolo[3,4-b]pyridine derivatives

Russian Chemical Bulletin, Journal Year: 2022, Volume and Issue: 71(5), P. 878 - 884

Published: May 1, 2022

Language: Английский

---

Process Development for a 1H-Indazole Synthesis Using an Intramolecular Ullmann-Type Reaction

The Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 88(7), P. 4209 - 4223

Published: March 23, 2023

Within the scope of developing a new route to an active pharmaceutical ingredient intermediate, we had need fluorinated indazole. Although established was in place, it undesirable due safety and selectivity concerns. A concise improved developed form desired indazole, which takes advantage electronically directed metalation/formylation sequence followed by condensation with methyl hydrazine hydrazone culminates copper-catalyzed intramolecular Ullmann cyclization. The reaction plagued difficulties ranging from poor reactivity thermal hazard concerns, but use high-throughput screening, statistical modeling, unusual isolation method for fine chemicals, safe optimal conditions were found that produce high-purity isolated material excellent yields at laboratory scale.

Language: Английский

---

Cobalt‐Promoted Para C─H Amination of 3‐Acetyl Substituted Nitroarenes with Arylhydrazines

ChemistrySelect, Journal Year: 2024, Volume and Issue: 9(43)

Published: Nov. 1, 2024

Abstract We report a method to furnish substituted 1H ‐indazoles via coupling of 3‐acetyl nitroarenes and arylhydrazines. Reactions progressed in the presence cobalt(II) acetylacetonate catalyst, TEMPO oxidant, Cs 2 CO 3 base. Functional groups including bromo, chloro, nitro, trifluoromethoxy were compatible with reaction conditions. The proposed mechanism was based on nucleophilic substitution hydrogen para nitro group. Our feature convenient pathway directly obtain which avoid use pre‐functionalized starting materials. Indazole could play role as directing group for palladium‐catalyzed C(sp )─H arylation iodobenzene.

Language: Английский

---

Copper (I) Catalysed Tandem C−C and C−N Bond Cleavage of N‐Fused Imidazoles towards the Synthesis of N‐pyridinylamides

ChemistrySelect, Journal Year: 2023, Volume and Issue: 8(13)

Published: April 3, 2023

Abstract Copper(I) catalysed oxidative conversion of imidazopyridines into N‐pyridinylamides has been achieved via tandem C−C and C−N bond cleavages under reaction conditions. The methodology wide substrate scope products were formed in good to excellent yields. This method is suitable for the both C‐3 functionalized as well non‐functionalized

Language: Английский

---

Tailor‐Made Pyrazolopyridines and Fused Pyrazolopyridines: Recent Updates toward Sustainable Synthesis

ChemistrySelect, Journal Year: 2024, Volume and Issue: 9(36)

Published: Sept. 1, 2024

Abstract Over the last three decades, owing to labour cost, time and especially environmental issues, one‐pot synthesis of heterocyclic compounds involving tandem or multicomponent (sequential consecutive) reactions has gained particular attention worldwide. Most marketed drug molecules hold one more rings. Due some side effects several drugs along with gradual emergence antimicrobial resistance, necessity for developing new continues; special should be paid in this respect towards employing their syntheses. Pyrazolopyridines are fused heterocycles holding pyridine pyrazole possess a wide variety biological pharmaceutical properties. Several existing also bear pyrazolopyridine scaffolds. The present perspective is an endeavour encompass green syntheses different isomeric systems, most these published during past five years few cases.

Language: Английский

---

1,1-Diaminoazine based Pd(II) NNN Pincer Complex: Generation, Characterization, and Application in Catalyzing the Acceptorless Dehydrogenative Coupling

Organic & Biomolecular Chemistry, Journal Year: 2024, Volume and Issue: unknown

Published: Jan. 1, 2024

An azine-based, non-palindromic, neutral NNN-pincer ligand was synthesised in a single step with yield of 85%.

Language: Английский

---