A Facile Approach to Catalyst-Free Cyanation and Azidation of ­Organic Compounds and a One-Pot Preparation of 5-Substituted 1H-Tetrazoles by Using a Dimethyl Sulfoxide–Nitric Acid Combination

Synlett ◽  
2019 ◽  
Vol 30 (20) ◽  
pp. 2290-2294
Author(s):  
Mohammad Ali Nasseri ◽  
Seyyedeh Ameneh Alavi ◽  
Boshra Mahmoudi ◽  
Milad Kazemnejadi
Keyword(s):  
Nitric Acid ◽  
Dimethyl Sulfoxide ◽  
Organic Compounds ◽  
Sodium Azide ◽  
Potassium Cyanide ◽  
Hydroxylamine Hydrochloride ◽  
One Pot ◽  
Mild Conditions ◽  
Tetrazole Derivatives

In this study, cyanations or azidations of imines were performed by using hydroxy(dimethyl)-λ4-sulfanecarbonitrile or azido(dimethyl)-λ4-sulfanol, respectively, prepared in situ by treatment of potassium cyanide or sodium azide with a dimethyl sulfoxide–nitric acid combination. Furthermore, a one-pot preparation of 5-substituted 1H-tetrazole derivatives was carried out by using this reagent combination in the presence of an aldehyde, hydroxylamine hydrochloride, and sodium azide under mild conditions.

A new approach to arylhydrazides via the reaction of the Mitsunobu reagent with arynes: further application to access diverse nitrogen-containing heterocycles in one pot

2017 ◽  
Vol 4 (8) ◽  
pp. 1636-1639 ◽  
Author(s):  
Bin Cheng ◽  
Bian Bao ◽  
Yanhe Chen ◽  
Ning Wang ◽  
Yun Li ◽  
...  
Keyword(s):  
One Pot ◽  
New Approach ◽  
Mild Conditions ◽  
Highly Active ◽  
Active Intermediates

A new route to arylhydrazides involving the reaction of two highly active intermediates, the 1,3-zwitterion generated in situ from the Mitsunobu reagent and arynes, under mild conditions has been developed.

scholarly journals Difunctionalization of alkenes with iodine and tert-butyl hydroperoxide (TBHP) at room temperature for the synthesis of 1-(tert-butylperoxy)-2-iodoethanes

2017 ◽  
Vol 13 ◽  
pp. 2023-2027 ◽  
Author(s):  
Hao Wang ◽  
Cui Chen ◽  
Weibing Liu ◽  
Zhibo Zhu
Keyword(s):  
Room Temperature ◽  
Synthetic Methods ◽  
Chemical Modifications ◽  
One Pot ◽  
Butyl Hydroperoxide ◽  
Radical Intermediates ◽  
Mild Conditions ◽  
Tert Butyl Hydroperoxide ◽  
Potential Applications

We developed a direct vicinal difunctionalization of alkenes with iodine and TBHP at room temperature. This iodination and peroxidation in a one-pot synthesis produces 1-(tert-butylperoxy)-2-iodoethanes, which are inaccessible through conventional synthetic methods. This method generates multiple radical intermediates in situ and has excellent regioselectivity, a broad substrate scope and mild conditions. The iodine and peroxide groups of 1-(tert-butylperoxy)-2-iodoethanes have several potential applications and allow further chemical modifications, enabling the preparation of synthetically valuable molecules.

scholarly journals Chemoselective activation of amide carbonyls towards nucleophilic reagents

2016 ◽  
Author(s):  
Bartłomiej Furman
Keyword(s):  
Chemical Biology ◽  
Grignard Reagents ◽  
Synthetic Method ◽  
Important Class ◽  
Selective Activation ◽  
One Pot ◽  
Mild Conditions ◽  
Nucleophilic Reagents ◽  
Danishefsky's Diene

Amides represent an important class of compounds in chemistry, chemical biology and pharmaceutical industry. Their broad utility in many fields is closely tied to the structure of the amide moiety which endows these compounds with unique features. The low reactivity of amide carbonyls towards nucleophiles is a major obstacle to their further functionalization. Selective activation of amides and lactams enables access to novel reactivity pathways and opens up intriguing perspectives in synthesis. Recently, we have demonstrated that upon treatment with Cp2Zr(H)Cl (Schwartz’s reagent), five- and six-membered lactams, including sugar- and hydroxy acid-derived lactams, can be easily converted into imines under mild conditions. In addition, as was also shown, in situ generated cyclic imines can be directly subjected to further reactions with nucleophilic reagents such as allyltributylstannane, Grignard reagents, enolates or Danishefsky’s diene to afford α-functionalized pyrrolidines, piperidines and polyhydroxylated pyrrolidine peptidomimetic scaffolds in a one-pot manner. The key advantage of the presented approach is the simplicity and convenience of generation of sugar-derived imines from readily available starting materials: sugar-derived lactams. The use of sugar-derived lactams as cyclic imine precursors is crucial to the efficiency of the described synthetic method. These compounds are more readily prepared, handled, and stored than the alternative precursors of cyclic imines such as nitrones, N-chloroamines or azido aldehydes. In the second part of the lecture a method for preparing 2,3-disubstituted indoles from commercially available isatins will be briefly presented.

Efficient Synthesis of Diverse 5-Thio- or 5-Selenotriazoles: One-Pot Multicomponent Reaction from Elemental Sulfur or Selenium

Synthesis ◽  
2019 ◽  
Vol 51 (22) ◽  
pp. 4170-4182 ◽  
Author(s):  
Lin-Lin Zhang ◽  
Ya-Ting Li ◽  
Ting Gao ◽  
Sha-Sha Guo ◽  
Bei Yang ◽  
...  
Keyword(s):  
Elemental Sulfur ◽  
Functional Group ◽  
High Efficiency ◽  
Efficient Synthesis ◽  
One Pot ◽  
Mild Conditions ◽  
Ligand Free ◽  
Multistep Reaction ◽  
Easy Operation

A sequential multistep reaction toward 5-thio- or 5-selenotriazoles has been established by generation of both copper(I) triazolides and sulfenylating or selenylating agents in situ, starting from elemental sulfur or selenium. This reaction features mild conditions, readily available and broad-scope substrates, good functional group compatibility, high efficiency and regioselectivity, easy operation, and ligand-free CuI.

scholarly journals Multicomponent versus domino reactions: One-pot free-radical synthesis of β-amino-ethers and β-amino-alcohols

2015 ◽  
Vol 11 ◽  
pp. 66-73 ◽  
Author(s):  
Bianca Rossi ◽  
Nadia Pastori ◽  
Simona Prosperini ◽  
Carlo Punta
Keyword(s):  
Free Radical ◽  
Cyclic Ether ◽  
Radical Addition ◽  
Domino Reaction ◽  
Alcohol Molecule ◽  
Secondary Products ◽  
Reaction Conditions ◽  
One Pot ◽  
Mild Conditions

Following an optimized multicomponent procedure, an aryl amine, a ketone, and a cyclic ether or an alcohol molecule are assembled in a one-pot synthesis by nucleophilic radical addition of ketyl radicals to ketimines generated in situ. The reaction occurs under mild conditions by mediation of the TiCl4/Zn/t-BuOOH system, leading to the formation of quaternary β-amino-ethers and -alcohols. The new reaction conditions guarantee good selectivity by preventing the formation of secondary products. The secondary products are possibly derived from a competitive domino reaction, which involves further oxidation of the ketyl radicals.

One-pot synthesis of novel N,N-bis(isoxazol-5-yl)methyl tertiary arylamines via sequential diprop-3-ynylation and 1,3-dipolar cycloaddition from primary amines

2019 ◽  
Vol 43 (9-10) ◽  
pp. 407-411 ◽  
Author(s):  
Xiao-Lan Zhang ◽  
Mei-Hong Wei ◽  
Shou-Ri Sheng ◽  
Xiao-Ling Liu
Keyword(s):  
Primary Amines ◽  
Dipolar Cycloaddition ◽  
Calcium Hydride ◽  
Methyl Groups ◽  
Propargyl Bromide ◽  
One Pot ◽  
Mild Conditions ◽  
Good Product ◽  
Easy Operation

A simple and efficient one-pot multicomponent approach for the synthesis of tertiary arylamines bearing N,N-bis(isoxazol-5-yl)methyl groups is developed through reactions including sequential diprop-3-ynylation of primary amines with propargyl bromide in the presence of calcium hydride in N,N-dimethylformamide, and 1,3-dipolar cycloaddition with nitrile oxides generated in situ from hydroximyl chlorides in DMF-Et3N. This protocol provides advantages such as high regioselectivity, easy operation, and moderate-to-good product yields with a wide substrate scope under mild conditions.

An Efficient Synthesis of Substituted Pyrazoles from One-Pot Reaction of Ketones, Aldehydes, and Hydrazine Monohydrochloride

Synlett ◽  
2018 ◽  
Vol 29 (08) ◽  
pp. 1071-1075 ◽  
Author(s):  
Vit Lellek ◽  
Cheng-yi Chen ◽  
Wanggui Yang ◽  
Jie Liu ◽  
Xuebao Ji ◽  
...  
Keyword(s):  
Efficient Synthesis ◽  
One Pot ◽  
Metal Free ◽  
Mild Conditions ◽  
Free Process ◽  
One Pot Condensation ◽  
Substituted Pyrazoles

An efficient, one-pot and metal-free process for the preparation of 3,5-disubstituted and 3,4,5-trisubstituted pyrazoles on multi-gram scale was developed. One-pot condensation of ketones, aldehydes and hydrazine monohydrochloride readily formed pyrazoline intermediates under mild conditions. Oxidation of pyrazolines, in situ, employing bromine afforded a wide variety of pyrazoles. The methodology offers a fast, and often chromatography-free protocol for the synthesis of 3,4,5-substituted pyrazoles in good to excellent yields. Alternatively, a more benign oxidation protocol affords 3,5-disubstituted or 3,4,5-trisubstituted pyrazoles by simply heating pyrazolines in DMSO under oxygen.

scholarly journals A two-phase bromination process using tetraalkylammonium hydroxide for the practical synthesis of α-bromolactones from lactones

2021 ◽  
Vol 17 ◽  
pp. 2906-2914
Author(s):  
Yuki Yamamoto ◽  
Akihiro Tabuchi ◽  
Kazumi Hosono ◽  
Takanori Ochi ◽  
Kento Yamazaki ◽  
...  
Keyword(s):  
Large Scale ◽  
Phase System ◽  
Methyl Ethyl ◽  
Two Phase ◽  
One Pot ◽  
Mild Conditions ◽  
Substoichiometric Amount ◽  
Practical Synthesis ◽  
Industrial Use

A simple and efficient method for α-brominating lactones that affords α-bromolactones under mild conditions using tetraalkylammonium hydroxide (R4N+OH−) as a base was developed. Lactones are ring-opened with Br2 and a substoichiometric amount of PBr3, leading to good yields of the corresponding α-bromocarboxylic acids. Subsequent intramolecular cyclization over 1 h using a two-phase system (H2O/CHCl3) containing R4N+OH− afforded α-bromo lactones in good yields. This method can be applied at the 10 mmol scale using simple operations. α-Bromo-δ-valerolactone, which is extremely reactive and difficult to isolate, could be isolated and stored in a freezer for about one week using the developed method. Optimizing the solvent for environmentally friendly large-scale syntheses revealed that methyl ethyl ketone (MEK) was as effective. In addition, in situ-generated α-bromo-δ-valerolactone was directly converted into a sulfur-substituted functional lactone without difficulty by reacting it with a sulfur nucleophile in one pot without isolation. This new bromination system is expected to facilitate the industrial use of α-bromolactones as important intermediates.

scholarly journals Chemoselective activation of amide carbonyls towards nucleophilic reagents

2016 ◽  
Author(s):  
Bartłomiej Furman
Keyword(s):  
Chemical Biology ◽  
Grignard Reagents ◽  
Synthetic Method ◽  
Important Class ◽  
Selective Activation ◽  
One Pot ◽  
Mild Conditions ◽  
Nucleophilic Reagents ◽  
Danishefsky's Diene

Amides represent an important class of compounds in chemistry, chemical biology and pharmaceutical industry. Their broad utility in many fields is closely tied to the structure of the amide moiety which endows these compounds with unique features. The low reactivity of amide carbonyls towards nucleophiles is a major obstacle to their further functionalization. Selective activation of amides and lactams enables access to novel reactivity pathways and opens up intriguing perspectives in synthesis. Recently, we have demonstrated that upon treatment with Cp2Zr(H)Cl (Schwartz’s reagent), five- and six-membered lactams, including sugar- and hydroxy acid-derived lactams, can be easily converted into imines under mild conditions. In addition, as was also shown, in situ generated cyclic imines can be directly subjected to further reactions with nucleophilic reagents such as allyltributylstannane, Grignard reagents, enolates or Danishefsky’s diene to afford α-functionalized pyrrolidines, piperidines and polyhydroxylated pyrrolidine peptidomimetic scaffolds in a one-pot manner. The key advantage of the presented approach is the simplicity and convenience of generation of sugar-derived imines from readily available starting materials: sugar-derived lactams. The use of sugar-derived lactams as cyclic imine precursors is crucial to the efficiency of the described synthetic method. These compounds are more readily prepared, handled, and stored than the alternative precursors of cyclic imines such as nitrones, N-chloroamines or azido aldehydes. In the second part of the lecture a method for preparing 2,3-disubstituted indoles from commercially available isatins will be briefly presented.

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.

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