Copper nanoparticles supported on charcoal mediated one-pot three-component synthesis of N-substituted-2H-indazoles via consecutive condensation C–N and N–N bond formation

2019 ◽  
Vol 97 (4) ◽  
pp. 303-309 ◽  
Author(s):  
Reza Khalifeh ◽  
Faranak Karimzadeh
Keyword(s):  
Copper Nanoparticles ◽  
Sodium Azide ◽  
Direct Synthesis ◽  
Bond Formation ◽  
Primary Amines ◽  
Title Reaction ◽  
One Pot

An efficient and straightforward protocol for direct synthesis of 2H-indazoles is achieved from consecutive condensation of 2-halobenzaldehydes, primary amines, and sodium azide catalyzed by heterogeneous copper nanoparticles on charcoal (Cu/C) is achieved. The recoverable heterogeneous copper nanoparticles on charcoal (Cu/C) catalyst exhibited an impressive activity for the title reaction without any additives (expensive ligands, etc.). A series of structurally diverse 2H-indazoles were prepared in good to excellent yields from easily accessible starting materials by employing this protocol.

scholarly journals N–N Bond Formation between Primary Amines and Nitrosos: Direct Synthesis of 2-Substituted Indazolones with Mechanistic Insights

2018 ◽  
Vol 20 (16) ◽  
pp. 4736-4739 ◽  
Author(s):  
Jie S. Zhu ◽  
Niklas Kraemer ◽  
Marina E. Shatskikh ◽  
Clarabella J. Li ◽  
Jung-Ho Son ◽  
...  
Keyword(s):  
Direct Synthesis ◽  
Bond Formation ◽  
Primary Amines

Microwave-assisted One-pot Synthesis of Amide Bond using WEB

2020 ◽  
Vol 7 (1) ◽  
pp. 50-59
Author(s):  
Kantharaju Kamanna ◽  
S.Y. Khatavi ◽  
P.B. Hiremath
Keyword(s):  
Carboxylic Acid ◽  
Microwave Irradiation ◽  
Primary Amine ◽  
Bond Formation ◽  
Amide Bond ◽  
Conventional Heating ◽  
Primary Amines ◽  
One Pot ◽  
Amide Bond Formation ◽  
One Pot Synthesis

Background: Amide bond plays a key role in medicinal chemistry, and the analysis of bioactive molecular database revealed that the carboxamide group appears in more than 25% of the existing database drugs. Typically amide bonds are formed from the union of carboxylic acid and amine; however, the product formation does not occur spontaneously. Several synthetic methods have been reported for amide bond formation in literature. Present work demonstrated simple and eco-friendly amide bond formation using carboxylic acid and primary amines through in situ generation of O-acylurea. The reaction was found to be more efficient, faster reaction rate; simple work-up gave pure compound isolation in moderate to excellent yield using microwave irradiation as compared to conventional heating. Methods: Developed one-pot synthesis of amide compounds using agro-waste derived greener catalyst under microwave irradiation. Results: Twenty amide bond containing organic compounds are synthesized from carboxylic acid with primary amine catalyzed by agro-waste derived medium under microwave irradiation. First, the reaction involved carboxylic acid activation using EDC.HCl, which is the required base for the neutralization and coupling. The method employed natural agro-waste derived from banana peel ash (WEB) for the coupling gave target amide product without the use of an external organic or inorganic base. Conclusion: In the present work, we demonstrated that agro-waste extract is an alternative greener catalytic medium for the condensation of organic carboxylic acid and primary amine under microwave irradiation. The method found several advantages compared to reported methods like solventfree, non-toxic, cheaper catalyst, and simple reaction condition. The final isolated product achieved chromatographically pure by simple recrystallization and did not require further purification.

scholarly journals Bimetallic copper and zinc-catalyzed oxidative cycloaddition of 3-aminopyridazines and nitriles: a direct synthesis of 1,2,4-triazolo[1,5-b]pyridazines via C–N and N–N bond-forming process

RSC Advances ◽  
2017 ◽  
Vol 7 (59) ◽  
pp. 37208-37213 ◽  
Author(s):  
Qiu-Chao Mu ◽  
Ji-Yuan Lv ◽  
Mu-Yi Chen ◽  
Xing-Feng Bai ◽  
Jing Chen ◽  
...  
Keyword(s):  
Direct Synthesis ◽  
Bond Formation ◽  
N Addition ◽  
Forming Process ◽  
One Pot ◽  
Bond Forming ◽  
Copper And Zinc ◽  
Pyridazine Derivatives

One-pot formation of 1,2,4-triazolo[1,5-b]pyridazine derivatives is presented in this manuscript, in which the targets are offered via cooperative Cu(i)/Zn(ii)-catalyzed tandem C–N addition and I2/KI-mediated intramolecular N–N bond formation.

Cu(NO3)2-catalysed Direct Synthesis of 5-substituted 1H-tetrazoles from Alcohols or Aldehydes

2017 ◽  
Vol 41 (1) ◽  
pp. 25-29 ◽  
Author(s):  
Chuanzhou Tao ◽  
Bin Wang ◽  
Lei Sun ◽  
Jiuyin Yi ◽  
Dahua Shi ◽  
...  
Keyword(s):  
Sodium Azide ◽  
Direct Synthesis ◽  
Nitrogen Sources ◽  
One Pot ◽  
Benzylic Alcohols ◽  
Substituted 1

A simple, convenient and practical protocol to synthesise 5-substituted 1 H-tetrazoles from alcohols or aldehydes is reported. Using ammonia and sodium azide as nitrogen sources and Cu(NO3)2 as catalyst, benzylic alcohols and benzaldehydes were directly converted into 5-substituted 1 H-tetrazoles in a one-pot procedure.

scholarly journals Microwave Assisted Expeditious and Green Cu(II)-Clay Catalyzed Domino One-Pot Three Component Synthesis of 2H-indazoles

2018 ◽  
Vol 13 (1) ◽  
pp. 82
Author(s):  
Bashir Ahmad Dar ◽  
Syed Wasim Safvi ◽  
Masood Ahmad Rizvi
Keyword(s):  
Reaction Engineering ◽  
Primary Amines ◽  
Efficient Synthesis ◽  
X Ray Diffraction ◽  
Title Reaction ◽  
One Pot ◽  
X Ray ◽  
Microwave Assisted ◽  
Clay Catalyst ◽  
Scanning Electron

A simple and efficient synthesis of 2H-indazoles is achieved from 2-primary amines, bromobenzaldehydes and sodium azide through domino condensation, C–N and N–N bond formations, catalyzed by a heterogeneous Cu(II)-Clay catalyst. The recyclable heterogeneous Cu(II)-Clay catalyst exhibited a remarkable activity for the title reaction without any additives. An assortment of structurally diverse 2H-indazoles were prepared in good to excellent yields from easily available starting materials by using this protocol. The Cu(II)-Clay catalyst was characterized by using X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Brunauer-Emmett-Teller (BET) techniques.  Copyright © 2018 BCREC Group. All rights reservedReceived: 24th February 2017; Revised: 8th August 2017; Accepted: 23rd August 2017; Available online: 22nd January 2018; Published regularly: 2nd April 2018How to Cite: Dar, B.A., Safvi, S.W., Rizvi, M.A. (2018). Microwave Assisted Expeditious and Green Cu(II)-Clay Catalyzed Domino One-Pot Three Component Synthesis of 2H-indazoles. Bulletin of Chemical Reaction Engineering & Catalysis, 13 (1): 82-88 (doi:10.9767/bcrec.13.1.963.82-88) 

scholarly journals Unmasked Primary Amines as C-Nucleophiles for Catalytic C–C Bond-Formation

2020 ◽  
Author(s):  
Alison Ryder ◽  
William Cunningham ◽  
George Ballantyne ◽  
Tom Mules ◽  
Anna Kinsella ◽  
...  
Keyword(s):  
Organic Synthesis ◽  
Direct Synthesis ◽  
Bond Formation ◽  
Hydrogen Atom Transfer ◽  
Primary Amines ◽  
Amino Group ◽  
Atom Economy ◽  
Critical Gap ◽  
Azide Ion

A practical, catalytic entry to α,α,α‑trisubstituted (α‑tertiary) primary amines by C–H functionalisation has long been recognised as a critical gap in the synthetic toolbox. We report a simple and scalable solution to this problem that does not require any <i>in situ</i> protection of the amino group and proceeds with 100% atom-economy. Our strategy, which uses an organic photocatalyst in combination with azide ion as a hydrogen atom transfer (HAT) catalyst, provides a direct synthesis of <i>C</i>-alkylated amines or γ‑lactams, including valuable azaspirocycles. We anticipate that this methodology will inspire new retrosynthetic disconnections for substituted amine derivatives in organic synthesis, and particularly for challenging α‑tertiary primary amines.

scholarly journals Unmasked Primary Amines as C-Nucleophiles for Catalytic C–C Bond-Formation

2020 ◽  
Author(s):  
Alison Ryder ◽  
William Cunningham ◽  
George Ballantyne ◽  
Tom Mules ◽  
Anna Kinsella ◽  
...  
Keyword(s):  
Organic Synthesis ◽  
Direct Synthesis ◽  
Bond Formation ◽  
Hydrogen Atom Transfer ◽  
Primary Amines ◽  
Amino Group ◽  
Atom Economy ◽  
Critical Gap ◽  
Azide Ion

A practical, catalytic entry to α,α,α‑trisubstituted (α‑tertiary) primary amines by C–H functionalisation has long been recognised as a critical gap in the synthetic toolbox. We report a simple and scalable solution to this problem that does not require any <i>in situ</i> protection of the amino group and proceeds with 100% atom-economy. Our strategy, which uses an organic photocatalyst in combination with azide ion as a hydrogen atom transfer (HAT) catalyst, provides a direct synthesis of <i>C</i>-alkylated amines or γ‑lactams, including valuable azaspirocycles. We anticipate that this methodology will inspire new retrosynthetic disconnections for substituted amine derivatives in organic synthesis, and particularly for challenging α‑tertiary primary amines.

α-Ketophosphonates in the Synthesis of α-iminophosphonates

2020 ◽  
Vol 7 (2) ◽  
pp. 226-238
Author(s):  
Petro P. Ony`sko ◽  
Tetyana I. Chudakova ◽  
Vladimir V. Pirozhenko ◽  
Alexandr B. Rozhenko
Keyword(s):  
Bond Cleavage ◽  
Direct Synthesis ◽  
Equilibrium Mixture ◽  
Primary Amines ◽  
Alkyl Amines ◽  
Protic Solvents ◽  
Metallic Salts ◽  
Direct Preparation ◽  
Stage Synthesis ◽  
Aprotic Dipolar Solvent

The potentialities of condensation of α-ketophosphonates with primary amines for direct synthesis of α-iminophosphonates have been revealed. Diesters of α-ketophosphonic acids react with the primary amines by two competitive pathways: with a formation of α-iminophosphonates or a C-P bond cleavage resulting in a hydrogen phosphonate and an acylated amine. In many cases, the latter undesirable pathway is dominant, especially for more nucleophilic alkyl amines. Using metallic salts of α-ketophosphonates avoids the C-P bond cleavage, allowing direct preparation of α-phosphorylated imines by the reaction with primary amines. This strategy provides an atom economy single-stage synthesis of iminophosphonates – precursors of bio relevant phosphorus analogs of α-amino acids. Methyl sodium iminophosphonates, bearing aryl or heteryl substituents at the imino carbon atom exist in solutions at room temperature as an equilibrium mixture of Z- and E-isomers. A configuration of the C=N bond can be controlled by the solvent: changing the aprotic dipolar solvent DMSO-d6 by water or alcohols leads to the change from a predominant Z-isomer to almost an exclusive E-form. In contrast, diesters of the respective iminophosphonates exist in non-protic solvents predominantly in Econfiguration. The solvent effect on E-Z stereochemistry is demonstrated by DFT calculations.

Microwave-accelerated Carbon-carbon and Carbon-heteroatom Bond Formation via Multi-component Reactions: A Brief Overview

2020 ◽  
Vol 7 (1) ◽  
pp. 23-39 ◽  
Author(s):  
Kantharaju Kamanna ◽  
Santosh Y. Khatavi
Keyword(s):  
Organic Synthesis ◽  
Bond Formation ◽  
Cycloaddition Reaction ◽  
Nanoparticle Synthesis ◽  
Single Step ◽  
Bioactive Molecules ◽  
One Pot ◽  
Bond Forming ◽  
Material Interest ◽  
Carbon Carbon Bond

Multi-Component Reactions (MCRs) have emerged as an excellent tool in organic chemistry for the synthesis of various bioactive molecules. Among these, one-pot MCRs are included, in which organic reactants react with domino in a single-step process. This has become an alternative platform for the organic chemists, because of their simple operation, less purification methods, no side product and faster reaction time. One of the important applications of the MCRs can be drawn in carbon- carbon (C-C) and carbon-heteroatom (C-X; X = N, O, S) bond formation, which is extensively used by the organic chemists to generate bioactive or useful material synthesis. Some of the key carbon- carbon bond forming reactions are Grignard, Wittig, Enolate alkylation, Aldol, Claisen condensation, Michael and more organic reactions. Alternatively, carbon-heteroatoms containing C-N, C-O, and C-S bond are also found more important and present in various heterocyclic compounds, which are of biological, pharmaceutical, and material interest. Thus, there is a clear scope for the discovery and development of cleaner reaction, faster reaction rate, atom economy and efficient one-pot synthesis for sustainable production of diverse and structurally complex organic molecules. Reactions that required hours to run completely in a conventional method can now be carried out within minutes. Thus, the application of microwave (MW) radiation in organic synthesis has become more promising considerable amount in resource-friendly and eco-friendly processes. The technique of microwaveassisted organic synthesis (MAOS) has successfully been employed in various material syntheses, such as transition metal-catalyzed cross-coupling, dipolar cycloaddition reaction, biomolecule synthesis, polymer formation, and the nanoparticle synthesis. The application of the microwave-technique in carbon-carbon and carbon-heteroatom bond formations via MCRs with major reported literature examples are discussed in this review.

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