Iodine-promoted Prins-cyclization of ketones — A facile synthesis of spirocyclic-4-iodo-tetrahydropyrans and 5,6-dihydro-2H-pyrans

2007 ◽  
Vol 85 (6) ◽  
pp. 412-415 ◽  
Author(s):  
J S Yadav ◽  
B V Subba Reddy ◽  
V Hari Krishna ◽  
T Swamy ◽  
GG KS Narayana Kumar
Keyword(s):  
Reaction Time ◽  
Ambient Temperature ◽  
High Selectivity ◽  
Molecular Iodine ◽  
Facile Synthesis ◽  
Prins Cyclization ◽  
Short Reaction Time ◽  
Homopropargylic Alcohols ◽  
High Yields

Homoallylic and homopropargylic alcohols undergo smooth coupling with ketones in the presence of molecular iodine at ambient temperature to produce spirocyclic-4-iodotetrahydropyrans and 5,6-dihydro-2H-pyrans, respectively, in high yields in a short reaction time with high selectivity. The use of molecular iodine makes this procedure quite simple, more convenient, and cost-effective.Key words: Prins-cyclization, iodine, homopropargylic alcohol, spirocyclic-4-iodopyrans.

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.

scholarly journals Facile Synthesis of Spiro[cyclohexane-1,3’-indoline]-2,2’-diones

2019 ◽  
Vol 25 (1) ◽  
pp. 157-161 ◽  
Author(s):  
Shin-taro Katayama ◽  
Hiroshi Nishino
Keyword(s):  
Natural Products ◽  
Reaction Time ◽  
Total Synthesis ◽  
Facile Synthesis ◽  
One Pot ◽  
Short Reaction Time ◽  
High Yields

AbstractSpiro[cyclohexane-1,3’-indoline]-2,2’-diones were easily prepared in good to high yields by the oxidation of N-aryl-N-methyl-2-oxocyclohexane-1-carboxamides in one pot with a short reaction time. The spiroindolinediones could be important for the total synthesis of natural products.

Nucleophilic Acylation with Aromatic Aldehydes to 2 Bromoacetonitrile: An Umpolung Strategy for the Synthesis of Active Methylene Compounds

2020 ◽  
Vol 17 (7) ◽  
pp. 518-524
Author(s):  
Shailesh Singh ◽  
Jyoti Tiwari ◽  
Deepali Jaiswal ◽  
Amit Kumar Sharma ◽  
Jaya Singh ◽  
...  
Keyword(s):  
Reaction Time ◽  
Ambient Temperature ◽  
Aromatic Aldehydes ◽  
Product Formation ◽  
One Pot ◽  
Short Reaction Time ◽  
Salient Features ◽  
High Yields ◽  
Operational Simplicity ◽  
Nucleophilic Acylation

Background: A novel one-pot N-heterocyclic carbene (NHC)-catalysed acylation of 2- bromoacetonitrile with aromatic aldehydes is reported. The protocol involves carbonyl umpolung reactivity of aldehydes in which the carbonyl carbon attacks nucleophilically (as d1 nucleophile) on the electrophilic terminal of 2-bromoacetonitrile to afford 3-aryl-3-oxopropanenitrile. The salient features of this procedure are short reaction time, operational simplicity, ambient temperature, no by-product formation and high yields. Materials and Methods: A flame-dried round bottom flask was charged with Imidazolium salts (3a) (0.20 mmol). Aldehyde 1a (1.0 mmol), 2-bromoacetonitrile 2 (1.0 mmol), and THF / t-BuOH 5 mL; 10:1) were added at positive nitrogen pressure followed by the addition of DBU (0.15 mmol) through stirring. The resulting yellow- orange solution was stirred at room temperature for 5-6 h. After completion of the reaction (TLC monitored), the reaction mixture was concentrated under reduced pressure. The product was purified using hexane / EtOAc (10:1) as an eluent to provide analytically pure compound 4a. Physical data of representative compounds and the NMR spectroscopic data are in agreement with the literature value. Results and Discussion: The salient features of this procedure are short reaction time, operational simplicity, ambient temperature, no by-product formation and high yields. Conclusion: To sum up, we have developed a convenient, efficient and one-pot route for 3-oxo-3- phenylpropanenitrile synthesis from NHC promoted direct nucleophilic acylation of aromatic aldehydes using 2- bromoacetonitrile. This method provided a wide range of products and good yields. To best of our knowledge, this is the new report for the synthesis of 3-oxo-3-phenylpropanenitrile through NHC promoted nucleophilic acylation of aromatic aldehyde.

Iodine-Mediated Multi-Component Reactions: Readily Access to Tetrazoles and Guanidines

2020 ◽  
Vol 17 ◽  
Author(s):  
Bajivali Shaik ◽  
Mohan Seelam ◽  
Ramana Tamminana ◽  
Prasad Rao Kammela
Keyword(s):  
Reaction Time ◽  
Benzoyl Chloride ◽  
Functional Group ◽  
Molecular Iodine ◽  
Environmentally Benign ◽  
Reaction Conditions ◽  
One Pot ◽  
Short Reaction Time ◽  
One Pot Synthesis ◽  
High Yields

Abstract: Environmentally benign syntheses of One-pot sequential reactions of benzoyl chloride with amines followed by the treatment of molecular I2 reagent under basic conditions provide benzoyl tetrazoles and guanidines in moderate to excel-lent yields. This one-pot synthesis has several advantages such as mild reaction conditions, short reaction time, convenient workup, high yields, using cheap and readily available reagent molecular Iodine. In addition, functional group tolerance has been explored

scholarly journals A Simple and Green Protocol for 2H-Indazolo[2,1-b]phthalazine-triones Using Grinding Method

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Xiao-chuan Jia ◽  
Jing Li ◽  
Yu Ding ◽  
Bin Zhang ◽  
Na Wang ◽  
...  
Keyword(s):  
Reaction Time ◽  
Sulfonic Acid ◽  
Catalytic Amount ◽  
Solvent Free ◽  
Short Reaction Time ◽  
Green Protocol ◽  
Simple Operation ◽  
Grinding Method ◽  
Toluene Sulfonic Acid ◽  
High Yields

A robust, facile, and solvent-free route for the three-component synthesis of 2H-indazolo[2,1-b]phthalazine-triones in the presence of a catalytic amount ofp-toluene sulfonic acid utilizing grinding has been developed. Short reaction time, simple operation, and high yields are the advantages of this protocol.

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 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 Microwave assisted synthesis of five membered nitrogen heterocycles

RSC Advances ◽  
2020 ◽  
Vol 10 (59) ◽  
pp. 36031-36041
Author(s):  
Gopinadh Meera ◽  
K. R. Rohit ◽  
Salim Saranya ◽  
Gopinathan Anilkumar
Keyword(s):  
Reaction Time ◽  
Nitrogen Heterocycles ◽  
Product Formation ◽  
Microwave Assisted Synthesis ◽  
Short Reaction Time ◽  
Microwave Assisted ◽  
High Yields

Microwave assisted synthesis of N-heterocycles with short reaction time, high yields and high product purities along with a decrease in the rate of by-product formation.

ZnO nanoparticles in the synthesis of AB ring core of camptothecin

2010 ◽  
Vol 64 (6) ◽  
Author(s):  
Selvaraj Roopan ◽  
Fazlur Nawaz Khan
Keyword(s):  
Zinc Oxide ◽  
Reaction Time ◽  
Zinc Oxide Nanoparticles ◽  
Oxide Nanoparticles ◽  
Short Reaction Time ◽  
High Yields ◽  
Work Up ◽  
First Time ◽  
Ab Ring ◽  
Ring Core

AbstractFor the first time, synthesis of AB ring core of camptothecin synthons such as (2-chloroquinolin-3-yl)methanols (Va-Vg) using zinc oxide nanoparticles is reported. The desired attractive products were obtained in high yields, short reaction time, using a simple work-up procedure with the purification of products by non-chromatographic methods.

scholarly journals Fe3O4@chitosan-tannic acid bionanocomposite as a novel nanocatalyst for the synthesis of pyranopyrazoles

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Maryam Kamalzare ◽  
Mohammad Reza Ahghari ◽  
Mohammad Bayat ◽  
Ali Maleki
Keyword(s):  
Reaction Time ◽  
Tannic Acid ◽  
High Performance ◽  
Catalytic Performance ◽  
Natural Material ◽  
Magnetic Nanocatalyst ◽  
Reaction Conditions ◽  
One Pot ◽  
Short Reaction Time ◽  
High Yields

AbstractRecently magnetic nanocatalyst has attracted considerable attention because of its unique properties, including high performance, easy separation from the reaction mixture, and recyclability. In this study, a novel magnetic bionanocomposite was synthesized with chitosan and tannic acid as a natural material. The synthesized bionanocatalyst was characterized by essential analysis. Fe3O4@chitosan-tannic acid as a heterogeneous nanocatalyst was successfully applied to synthesize pyranopyrazole and its derivatives by a one-pot four-component reaction of malononitrile, ethyl acetoacetate, hydrazine hydrate, and various aromatic aldehyde. At the end of the reaction, the nanocatalyst was separated from the reaction mixture and was reused several times with no significant decrease in its catalytic performance. Simple purification of products, the ability for recovering and reusing the nanocatalyst, eco-friendliness, high yields of pure products, mild reaction conditions, short reaction time, non-toxicity, economically affordable are some of the advantages of using the fabricated nanocatalyst in the synthesis of pyranopyrazole.

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