Highly regioselective synthesis of 4-tosylthiomorpholine via intramolecular cyclization of N-tethered thioalkenols

2016 ◽  
Vol 14 (44) ◽  
pp. 10489-10495 ◽  
Author(s):  
Anil K. Saikia ◽  
Manash J. Deka ◽  
Upasana Borthakur
Keyword(s):  
Intramolecular Cyclization ◽  
Regioselective Synthesis ◽  
Elimination Reaction ◽  
One Pot ◽  
Metal Free ◽  
Subsequent Elimination

A one-pot, metal-free procedure has been developed for the synthesis of 4-tosylthiomorpholine from N-tethered thioalkenols via bromination, cyclization and subsequent elimination reaction in good yields. The reaction is highly regioselective.

Iodine-mediated C–N and C–S bond formation: regioselective synthesis of benzo[4,5]imidazo[2,1-b]thiazoles

2017 ◽  
Vol 41 (1) ◽  
pp. 75-80 ◽  
Author(s):  
Sethurajan Ambethkar ◽  
Muthalu Vellimalai ◽  
Vediappen Padmini ◽  
Nattamai Bhuvanesh
Keyword(s):  
Reaction Time ◽  
Intramolecular Cyclization ◽  
Simple Procedure ◽  
Bond Formation ◽  
Molecular Iodine ◽  
Regioselective Synthesis ◽  
Thiazole Derivatives ◽  
Short Reaction Time ◽  
Metal Free

The regioselective synthesis of benzo[4,5]imidazo[2,1-b]thiazole derivatives via amination (C–N) and intramolecular cyclization (C–S) reactions in the presence of molecular iodine has been reported. This method is base and metal free and features inexpensive catalysts, with a simple procedure and a short reaction time.

A transition metal-free approach towards the regioselective synthesis of β-carboline tethered pyrroles and 2,3-dihydro-1H-pyrroles

2020 ◽  
Vol 44 (28) ◽  
pp. 12370-12383
Author(s):  
Manpreet Singh ◽  
Avijit Kumar Paul ◽  
Virender Singh
Keyword(s):  
Transition Metal ◽  
Regioselective Synthesis ◽  
One Pot ◽  
Sequential Approach ◽  
Metal Free

A transition metal-free one-pot sequential approach has been unfolded for the synthesis of β-carboline tethered pyrroles and 2,3-dihydro-1H-pyrroles by using highly diverse 1-formyl-9H-β-carbolines as a template.

Transition-metal-free multinitrogenation of amides by C–C bond cleavage: a new approach to tetrazoles

2018 ◽  
Vol 54 (79) ◽  
pp. 11148-11151 ◽  
Author(s):  
Lian-Hua Li ◽  
Zhi-Jie Niu ◽  
Ying-Xiu Li ◽  
Yong-Min Liang
Keyword(s):  
Transition Metal ◽  
Bond Cleavage ◽  
Regioselective Synthesis ◽  
One Pot ◽  
New Approach ◽  
Metal Free

A metal-free brand-new one-pot multinitrogenation of amides for the chemo-, regioselective synthesis of 1,5-disubstituted tetrazoles has been developed.

Ionic Liquid Catalyzed Efficient Regioselective Synthesis of 1,4- Disubstituted 1,2,3-Triazoles under Metal and Solvent free Conditions

2020 ◽  
Vol 07 ◽  
Author(s):  
Abid H. Banday ◽  
Victor J. Hruby
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Solvent Free ◽  
Regioselective Synthesis ◽  
Chromatographic Separations ◽  
One Pot ◽  
Green Protocol ◽  
Metal Free ◽  
Organic Azides ◽  
Solvent Free Conditions

Background: Unprecedented, one-pot regioselective synthesis of 1,4-disubstituted 1,2,3-triazoles through azide- aldehyde (3+2) organo-click cycloaddition under metal and solvent-free conditions, is described. Objective: Solvent and metal free synthesis of biologically and industrially important triazoles. Methods: Efficient and high yielding synthesis of products avoiding the tedious high solvent workups and chromatographic separations. The synthesis doesn’t involve the routine acetylenes which are very costly but instead cheaper starting materials like aldehydes and organic azides are used. Results: Green protocol based on the catalysis through Ionic Liquids which simultaneously act as solvents. The products are obtained in good to excellent yields in hassle free synthesis. Conclusion: Efficient and green synthesis of structurally and biologically important triazoles.

Metal-free, visible-light-promoted oxidative radical cyclization of N-biarylglycine esters: one-pot construction of phenanthridine-6-carboxylates in water

2019 ◽  
Vol 21 (16) ◽  
pp. 4406-4411 ◽  
Author(s):  
Palani Natarajan ◽  
Deachen Chuskit ◽  
Priya Priya
Keyword(s):  
Visible Light ◽  
Intramolecular Cyclization ◽  
Radical Cyclization ◽  
Cyclization Reaction ◽  
Ambient Conditions ◽  
One Pot ◽  
Light Blue ◽  
Metal Free ◽  
Air Atmosphere ◽  
Oxidative Radical Cyclization

A metal-free, visible-light (blue LED: hν = 425 ± 15 nm) photoredox-catalyzed intramolecular cyclization reaction of N-biarylglycine esters to phenanthridine-6-carboxylates in water under an open air atmosphere at ambient conditions has been developed.

An efficient one-pot strategy for the highly regioselective metal-free synthesis of 1,4-disubstituted-1,2,3-triazoles

2014 ◽  
Vol 50 (80) ◽  
pp. 11926-11929 ◽  
Author(s):  
Akbar Ali ◽  
Arlene G. Corrêa ◽  
Diego Alves ◽  
Julio Zukerman-Schpector ◽  
Bernhard Westermann ◽  
...  
Keyword(s):  
Regioselective Synthesis ◽  
Dipolar Cycloaddition ◽  
One Pot ◽  
Inverse Electron Demand ◽  
Metal Free ◽  
Electron Demand

A simple and efficient metal-free methodology for the regioselective synthesis of 1,4-disubstituted-1,2,3-triazoles by applying a novel inverse electron-demand-1,3-dipolar cycloaddition approach has been developed.

Conjugate systems in the construction of heterocycles and quaternary stereocenters

2007 ◽  
Vol 79 (2) ◽  
pp. 181-191 ◽  
Author(s):  
Carlos González-Romero ◽  
Pablo Bernal ◽  
Fabiola Jiménez ◽  
María del Carmen Cruz ◽  
Aydeé Fuentes-Benites ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Intramolecular Cyclization ◽  
Regioselective Synthesis ◽  
The Novel ◽  
One Pot ◽  
Naturally Occurring ◽  
Novel Approach ◽  
Michael Acceptors ◽  
Quaternary Stereocenters ◽  
Synthetic Application

The synthetic application of 4,5-bis-alkylidene-1,3-oxazolidin-2-ones led to the efficient and regioselective synthesis of 2-(3H)-benzoxazolones and diarylamines with a short methodology. They were also valuable synthons in a total synthesis of naturally occurring carbazoles. New enantiopure 4-oxazoline-2-one and 4-methylene-2-oxazolidinone were prepared via a one-pot microwave (MW)-promoted condensation of α-ketols and an enantiopure isocyanate. These enamides were efficient nucleophiles when added to Michael acceptors to give a series of compounds with quaternary stereocenters in fairly good stereoisomeric ratios. The novel approach for the synthesis of benzofurans and indoles by intramolecular cyclization of enaminones has been applied in the preparation of furobenzofurans starting from benzo-bis-enaminones.

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