An Expeditious Route for the Synthesis of Oxazepine Triazolo-β-Lactams through Intramolecular Metal-Free [3+2] Azide–Alkyne Cycloaddition

2020 ◽  
Vol 73 (7) ◽  
pp. 654
Author(s):  
Ram N. Yadav ◽  
Sunena Chandra ◽  
Armando Paniagua ◽  
Md. Firoj Hossain ◽  
Bimal Krishna Banik
Keyword(s):  
Sodium Azide ◽  
Good Yield ◽  
Cycloaddition Reaction ◽  
Present Approach ◽  
One Pot ◽  
Metal Free ◽  
Internal Alkynes

A copper-free intramolecular azide–alkyne cycloaddition reaction of 4-hydroxymethyl-β-lactam with sodium azide has been described. The present approach involves the incorporation of an alkyne moiety through O-alkynylation of 3-hydroxy β-lactam with various propargylic halides. The generality of the method has been demonstrated by treating the corresponding tosylates or mesylates of the hydroxymethyl functionality of a variety of β-lactam-tethered terminal and internal alkynes with sodium azide in a one-pot three-step reaction to furnish novel oxazepane-β-lactam fused triazole scaffolds of diverse interest in good yield.

scholarly journals Synthesis of a Novel Series of Cu(I) Complexes Bearing Alkylated 1,3,5-Triaza-7-phosphaadamantane as Homogeneous and Carbon-Supported Catalysts for the Synthesis of 1- and 2-Substituted-1,2,3-triazoles

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2702
Author(s):  
Ivy L. Librando ◽  
Abdallah G. Mahmoud ◽  
Sónia A. C. Carabineiro ◽  
M. Fátima C. Guedes da Silva ◽  
Carlos F. G. C. Geraldes ◽  
...  
Keyword(s):  
Aqueous Medium ◽  
Sodium Azide ◽  
Supported Catalysts ◽  
Cycloaddition Reaction ◽  
Water Soluble ◽  
Terminal Alkynes ◽  
One Pot ◽  
Catalytic Systems ◽  
Immobilized Catalyst ◽  
High Yields

The N-alkylation of 1,3,5-triaza-7-phosphaadamantane (PTA) with ortho-, meta- and para-substituted nitrobenzyl bromide under mild conditions afforded three hydrophilic PTA ammonium salts, which were used to obtain a new set of seven water-soluble copper(I) complexes. The new compounds were fully characterized and their catalytic activity was investigated for the low power microwave assisted one-pot azide–alkyne cycloaddition reaction in homogeneous aqueous medium to obtain disubstituted 1,2,3-triazoles. The most active catalysts were immobilized on activated carbon (AC), multi-walled carbon nanotubes (CNT), as well as surface functionalized AC and CNT, with the most efficient support being the CNT treated with nitric acid and NaOH. In the presence of the immobilized catalyst, several 1,4-disubstituted-1,2,3-triazoles were obtained from the reaction of terminal alkynes, organic halides and sodium azide in moderate yields up to 80%. Furthermore, the catalyzed reaction of terminal alkynes, formaldehyde and sodium azide afforded 2-hydroxymethyl-2H-1,2,3-triazoles in high yields up to 99%. The immobilized catalyst can be recovered and recycled through simple workup steps and reused up to five consecutive cycles without a marked loss in activity. The described catalytic systems proceed with a broad substrate scope, under microwave irradiation in aqueous medium and according to “click rules”.

One-pot transition-metal free transamidation to sterically hindered amides

2018 ◽  
Vol 5 (20) ◽  
pp. 2950-2954 ◽  
Author(s):  
Weijie Guo ◽  
Jingjun Huang ◽  
Hongxiang Wu ◽  
Tingting Liu ◽  
Zhongfeng Luo ◽  
...  
Keyword(s):  
Transition Metal ◽  
Good Yield ◽  
One Pot ◽  
Metal Free ◽  
Highly Efficient ◽  
Sterically Hindered

A highly efficient one-pot transamidation of primary amides has been developed under transition-metal free conditions, generating a variety of amides including hindered amides in good yield (up to 86%) catalyzed by CsF.

A rapid metal free synthesis of 5-substituted-1H-tetrazoles using cuttlebone as a natural high effective and low cost heterogeneous catalyst

RSC Advances ◽  
2015 ◽  
Vol 5 (62) ◽  
pp. 49849-49860 ◽  
Author(s):  
Sara S. E. Ghodsinia ◽  
Batool Akhlaghinia
Keyword(s):  
Heterogeneous Catalyst ◽  
Sodium Azide ◽  
High Efficiency ◽  
Low Cost ◽  
Cycloaddition Reaction ◽  
Metal Free ◽  
Substituted 1

A convenient, rapid and metal free synthesis of 5-substituted-1H-tetrazoles by [3 + 2] cycloaddition reaction of nitriles with sodium azide. Cuttlebone as a natural low cost heterogeneous catalyst affords 5-substituted-1H-tetrazoles rapidly with high efficiency.

One-Pot Synthesis of [1,2,3]Triazolo[1,5-a]quinoxalin-4(5H)-ones by a Metal-Free Sequential Ugi-4CR/Alkyne–Azide Cycloaddition Reaction

Synlett ◽  
2019 ◽  
Vol 31 (01) ◽  
pp. 73-76 ◽  
Author(s):  
Yan-Mei Yan ◽  
Hao-Yang Li ◽  
Min Zhang ◽  
Rong-Xin Wang ◽  
Chen-Guang Zhou ◽  
...  
Keyword(s):  
Cycloaddition Reaction ◽  
One Pot ◽  
Metal Free ◽  
One Pot Synthesis

A convenient and one-pot approach to prepare [1,2,3]triazolo[1,5-a]quinoxalin-4(5H)-ones by a metal-free sequential Ugi-4CR/alkyne–azide cycloaddition reaction has been developed. The reaction of 2-azidobenzenamines, aldehydes, propiolic acids, and isocyanides produced the Ugi adducts, which were transformed to the [1,2,3]triazolo[1,5-a]quinoxalin-4(5H)-ones in moderate to good yields via alkyne–azide cycloaddition reaction.

scholarly journals Highly Active and Reusable Cu/C Catalyst for Synthesis of 5-Substituted 1H-Tetrazoles Starting from Aromatic Aldehydes

2020 ◽  
Vol 67 (4) ◽  
pp. 1044-1052
Author(s):  
Reza Khalifeh ◽  
Najme Rastegar ◽  
Dariush Khalili
Keyword(s):  
Sodium Azide ◽  
Cycloaddition Reaction ◽  
Aromatic Aldehydes ◽  
Significant Loss ◽  
One Pot ◽  
Highly Active ◽  
Wide Range ◽  
Simple Filtration ◽  
The One ◽  
Tetrazole Derivatives

A new, efficient and convenient method for the synthesis of 5-substituted 1H-tetrazole derivatives with a wide range of substituents in good to excellent yields has been developed. The synthesis was performed by the one-pot three-component [3+2]cycloaddition reaction between aldehyde, hydroxylamine and sodium azide in the presence of Cu/C. The reaction probably proceeds by the in situ formation of nitriles followed by successive [3+2]cycloaddition with sodium azide. A variety of aldehydes were used to obtain the corresponding tetrazoles. The catalyst was recovered by simple filtration and reused at least five times without significant loss of catalytic activity. The use of this method offers additional advantages for the synthesis of 5-substituted 1H-tetrazole derivatives, including the easy availability of starting materials, mild conditions, experimental simplicity and good yields.

A New Protocol for Total Synthesis of Natural Product Frutinone A and Its Derivatives

2016 ◽  
Vol 69 (1) ◽  
pp. 98 ◽  
Author(s):  
Kang Lei ◽  
Dong-Wei Sun ◽  
Yuan-Yuan Tao ◽  
Xiao-Hua Xu
Keyword(s):  
Total Synthesis ◽  
Natural Product ◽  
Good Yield ◽  
Substitution Reaction ◽  
High Tolerance ◽  
Synthetic Route ◽  
Reaction Conditions ◽  
One Pot ◽  
Metal Free ◽  
Intramolecular Nucleophilic Substitution

A new protocol for total synthesis of natural product frutinone A was accomplished in three steps by using inexpensive 2′-hydroxyacetophenone as starting material. The key intermediate 3-(2-chlorobenzoyl)-4-hydroxycoumarin was synthesized in one pot through Baker–Venkataraman rearrangement of 2-acetylphenyl 2-chlorobenzoate followed by introduction of methyl chloroformate under basic conditions. Then, base-promoted intramolecular nucleophilic substitution reaction of 3-(2-chlorobenzoyl)-4-hydroxycoumarin provided frutinone A in excellent yield. The synthetic route features good yield, transition metal-free and mild reaction conditions, and high tolerance for functionality, thereby allowing easy substitutions around the frutinone A core.

One-pot synthesis of α,β-epoxy ketones through domino reaction between alkenes and aldehydes catalyzed by proline based chiral organocatalysts

2017 ◽  
Vol 15 (12) ◽  
pp. 2551-2561 ◽  
Author(s):  
Veeramanoharan Ashokkumar ◽  
Ayyanar Siva
Keyword(s):  
Good Yield ◽  
Bond Formation ◽  
Direct Access ◽  
Domino Reaction ◽  
One Pot ◽  
New Approach ◽  
Metal Free ◽  
One Pot Synthesis ◽  
Epoxy Ketones

A proline based metal free organocatalysts developed by new approach for the synthesis of epoxide derivatives through domino reaction. This domino reaction allows the direct access to epoxide from various alkene and aldehyde through C–H functionalization and C–C/C–O bond formation. The catalytic efficiencies of organocatalysts were also determined by domino reaction with very good yield (up to 95 %) and ee's (up to 99 %).

Metal-Free Photoinduced Hydroalkylation Cascade Enabled by an Electron-Donor-Acceptor Complex

2020 ◽  
Author(s):  
José Tiago Menezes Correia ◽  
Gustavo Piva da Silva ◽  
Camila Menezes Kisukuri ◽  
Elias André ◽  
Bruno Pires ◽  
...  
Keyword(s):  
Electron Donor ◽  
Functional Group ◽  
Photoexcited Electron ◽  
One Pot ◽  
Quaternary Centers ◽  
Metal Free ◽  
Acceptor Complex ◽  
Catalyst Free ◽  
Donor Acceptor ◽  
Radical Cascade

A metal- and catalyst-free photoinduced radical cascade hydroalkylation of 1,7-enynes has been disclosed. The process is triggered by a SET event involving a photoexcited electron-donor-aceptor complex between NHPI ester and Hantzsch ester, which decomposes to afford a tertiary radical that is readily trapped by the enyne. <a>The method provides an operationally simple, robust and step-economical approach to the construction of diversely functionalized dihydroquinolinones bearing quaternary-centers. A sequential one-pot hydroalkylation-isomerization approach is also allowed giving access to a family of quinolinones. A wide substrate scope and high functional group tolerance was observed in both approaches</a>.

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