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.

Molecular iodine-catalysed amidation reaction of secondary benzylic and allylic alcohols with carboxamides or sulfonamides

2009 ◽  
Vol 2009 (10) ◽  
pp. 638-641 ◽  
Author(s):  
Xufeng Lin ◽  
Jun Wang ◽  
Fangxi Xu ◽  
Yanguang Wang
Keyword(s):  
Reaction Time ◽  
Efficient Method ◽  
Bond Formation ◽  
Molecular Iodine ◽  
Allylic Alcohols ◽  
Reaction Conditions ◽  
Short Reaction Time ◽  
Metal Free ◽  
Amidation Reaction ◽  
Operational Simplicity

A highly efficient method for the C–N bond formation via 2 mol% of molecular iodine-catalysed amidation reaction of benzylic and allylic alcohols with carboxamides or sulfonamides in MeCN is described, giving the corresponding substituted amides and allylic amides in moderate to excellent yields. The significan features of the procedure include mild and metal-free reaction conditions, operational simplicity, inexpensive reagents, short reaction time, and good yields.

A Convenient Synthesis of 1,5-Fused 1,2,4-Triazoles from N-Arylamidines via Chloramine-T Mediated Intramolecular Oxidative N–N Bond Formation

Synthesis ◽  
2019 ◽  
Vol 51 (20) ◽  
pp. 3883-3890
Author(s):  
Ashish Bhatt ◽  
Rajesh K. Singh ◽  
Ravi Kant ◽  
Bhupendra K. Sarma
Keyword(s):  
Reaction Time ◽  
Bond Formation ◽  
Available N ◽  
Short Reaction Time ◽  
Metal Free ◽  
Convenient Synthesis ◽  
Chloramine T ◽  
High Yields ◽  
Short Time

A convenient synthesis of 1,5-fused 1,2,4-triazoles from readily available N-arylamidines is reported. The reaction is efficiently promoted by chloramine-T to afford the desired products mostly in high yields and in relatively short time, through direct metal-free oxidative N−N bond formation. The mild nature of the synthesis and short reaction time are notable advantages of the developed protocol. This protocol is effective toward various substrates having different functionalities.

scholarly journals Base-Catalyzed Synthesis of Flavones via Thiol-Assisted Sequential Demethylation/Cyclization of 1-(2-methoxyphenyl)prop-2-yn-1-ones

2021 ◽  
Author(s):  
Ritiele Heck ◽  
Thiago Anjos ◽  
Maira R Giehl ◽  
Ricardo F Schumacher ◽  
Benhur Godoi
Keyword(s):  
Reaction Time ◽  
Secondary Metabolites ◽  
Transition Metal ◽  
Intramolecular Cyclization ◽  
Important Class ◽  
Short Reaction Time ◽  
Metal Free ◽  
Synthetic Strategy ◽  
Pharmacologically Active ◽  
Active Substances

Flavone and analogues represent an important class of biologically and pharmacologically active substances commonly found in the composition of diverse plants as part of the class of secondary metabolites. Herein, we have demonstrated an efficient and regioselective synthetic strategy for the preparation of functionalized flavones through sequential demethylation/6-endo-dig intramolecular cyclization of propyn-1-ones, using catalytic amounts of base in the presence of a thiol, by employing NMP as the solvent. The reactions proceeded smoothly under transition-metal-free and open to air conditions, furnishing the desired six-membered heterocycles in moderate to excellent yields, in short reaction time.

scholarly journals Green synthesis of 2-aryl-4-phenyl-quınazolıne derıvatives promoted by lactıc acıd

2017 ◽  
Vol 36 (2) ◽  
pp. 223 ◽  
Author(s):  
Belgheis Adrom ◽  
Nourallah Hazeri ◽  
Malek Taher Maghsoodlou ◽  
Mojtaba Lashkari ◽  
Maryam Fatahpour
Keyword(s):  
Lactic Acid ◽  
Reaction Time ◽  
Green Synthesis ◽  
Ammonium Acetate ◽  
Simple Procedure ◽  
Environmentally Benign ◽  
Synthetic Method ◽  
Short Reaction Time ◽  
Quinazoline Derivatives ◽  
Work Up

An environmentally benign three-component synthetic method is described for the construction of 2-aryl-4-phenylquinazoline derivatives from the reaction between aldehydes, ammonium acetate, and 2-aminobenzophenone in the presence of lactic acid in a solvent-less media. The benefits of the reaction were good yields, a simple procedure, simple starting materials short reaction time, easy work-up, and cleaner reaction profiles.

scholarly journals A Green, Expeditious, One-Pot Synthesis of 3, 4-Dihydropyrimidin-2(1H)-ones Using a Mixture of Phosphorus Pentoxide-Methanesulfonic Acid at Ambient Temperature

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Amulrao Borse ◽  
Mahesh Patil ◽  
Nilesh Patil ◽  
Rohan Shinde
Keyword(s):  
Reaction Time ◽  
Ambient Temperature ◽  
Room Temperature ◽  
Simple Procedure ◽  
Methanesulfonic Acid ◽  
Phosphorus Pentoxide ◽  
One Pot ◽  
Short Reaction Time ◽  
Solvent Free Conditions ◽  
High Yields

An expeditious, one-pot method for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones using a mixture of phosphorus pentoxide-methanesulfonic acid (Eaton’s reagent) at room temperature under solvent-free conditions is described. The salient features of this method include short reaction time, green aspects, high yields, and simple procedure.

Microwave-assisted regioselective synthesis of acyclic nucleosides through an alkylating reaction with 2-oxa-1,4-butanediol diacetate

2006 ◽  
Vol 84 (5) ◽  
pp. 819-824 ◽  
Author(s):  
Guirong Qu ◽  
Suhui Han ◽  
Zhiguang Zhang ◽  
Mingwei Geng ◽  
Feng Xue
Keyword(s):  
Reaction Time ◽  
Microwave Irradiation ◽  
Regioselective Synthesis ◽  
Environmental Friendliness ◽  
Short Reaction Time ◽  
Microwave Assisted ◽  
Acyclic Nucleosides ◽  
Green Procedure ◽  
Simple Manipulation

An efficient and green procedure for the synthesis of purine acyclic nucleosides through microwave-assisted alkylation of various purine nucleobases with 2-oxa-1,4-butanediol diacetate in the absence of solvent and catalyst is described. The advantages of using this method include its environmental friendliness, simple manipulation, short reaction time, high regioselectivity, and good yields.Key words: acyclic nucleosides, microwave irradiation, regioselectivity, alkylation, 2-oxa-1,4-butanediol diacetate.

One-pot synthesis of 2-amino-3-cyano-4-arylsubstituted tetrahydrobenzo[b]pyrans catalysed by silica gel-supported polyphosphoric acid (PPA-SiO2) as an efficient and reusable catalyst

2011 ◽  
Vol 65 (5) ◽  
Author(s):  
Abolghasem Davoodnia ◽  
Sadegh Allameh ◽  
Samineh Fazli ◽  
Niloofar Tavakoli-Hoseini
Keyword(s):  
Reaction Time ◽  
Silica Gel ◽  
Convenient Method ◽  
Polyphosphoric Acid ◽  
Simple Procedure ◽  
Reusable Catalyst ◽  
One Pot ◽  
Short Reaction Time ◽  
Aryl Aldehydes ◽  
High Yields

AbstractA convenient method for the synthesis of tetrahydrobenzo[b]pyrans by a one-pot three-component cyclocondensation of dimedone, aryl aldehydes, and malononitrile in water using silica gel-supported polyphosphoric acid (PPA-SiO2) as an efficient and reusable catalyst is described. The present methodology offers several advantages, such as a simple procedure with ease of handling, short reaction time, high yields, and the absence of any volatile and hazardous organic solvents.

Oxidative organophotoredox catalysis: a regioselective synthesis of 2-nitro substituted imidazopyridines and 3-substituted indoles, initiated by visible light

2016 ◽  
Vol 40 (11) ◽  
pp. 9694-9701 ◽  
Author(s):  
Snehlata Yadav ◽  
Madhulika Srivastava ◽  
Pratibha Rai ◽  
Bhartendu Pati Tripathi ◽  
Anu Mishra ◽  
...  
Keyword(s):  
Visible Light ◽  
Visible Light Irradiation ◽  
Room Temperature ◽  
Bond Formation ◽  
Light Irradiation ◽  
Regioselective Synthesis ◽  
Metal Free

Intramolecular C–N heterocyclization and C–C bond formation under visible light irradiation at room temperature was accomplished with a metal-free photoredox catalyst.

scholarly journals Pentafluoropropionic Acid: An Efficient and Metal-Free Catalyst for the One-Pot Synthesis of Tetrahydrobenzo[b]pyran Derivatives

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Naser Montazeri ◽  
Taghva Noghani ◽  
Mona Ghorchibeigy ◽  
Rozita Zoghi
Keyword(s):  
Reaction Time ◽  
Aromatic Aldehyde ◽  
One Pot ◽  
Short Reaction Time ◽  
Metal Free ◽  
One Pot Synthesis ◽  
Three Component Reaction ◽  
The One ◽  
High Yields

Pentafluoropropionic acid (PFPA) efficiently catalyzes the one-pot, three-component reaction of aromatic aldehyde, malononitrile, and dimedone to yield tetrahydrobenzo[b]pyran derivatives in high yields. This method is of great value because of its easy processing, short reaction time, environmentally, and high yields.

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