scholarly journals Orthogonal protection of saccharide polyols through solvent-free one-pot sequences based on regioselective silylations

2016 ◽  
Vol 12 ◽  
pp. 2748-2756 ◽  
Author(s):  
Serena Traboni ◽  
Emiliano Bedini ◽  
Alfonso Iadonisi
Keyword(s):  
Organic Synthesis ◽  
Tetrabutylammonium Bromide ◽  
Catalytic Amount ◽  
Building Blocks ◽  
Solvent Free ◽  
One Pot ◽  
Solvent Free Conditions ◽  
Wide Range ◽  
Regioselective Silylation ◽  
Short Times

tert-Butyldimethylsilyl (TBDMS) and tert-butyldiphenylsilyl (TBDPS) are alcohol protecting groups widely employed in organic synthesis in view of their compatibility with a wide range of conditions. Their regioselective installation on polyols generally requires lengthy reactions and the use of high boiling solvents. In the first part of this paper we demonstrate that regioselective silylation of sugar polyols can be conducted in short times with the requisite silyl chloride and a very limited excess of pyridine (2–3 equivalents). Under these conditions, that can be regarded as solvent-free conditions in view of the insolubility of the polyol substrates, the reactions are faster than in most examples reported in the literature, and can even be further accelerated with a catalytic amount of tetrabutylammonium bromide (TBAB). The strategy proved also useful for either the selective TBDMS protection of secondary alcohols or the fast per-O-trimethylsilylation of saccharide polyols. In the second part of the paper the scope of the silylation approach was significantly extended with the development of unprecedented “one-pot” and “solvent-free” sequences allowing the regioselective silylation/alkylation (or the reverse sequence) of saccharide polyols in short times. The developed methodologies represent a very useful and experimentally simple tool for the straightforward access to saccharide building-blocks useful in organic synthesis.

One-Pot, Regioselective Synthesis of Homopropargyl Alcohols using Propargyl Bromide and Carbonyl Compound by the Mg-mediated Reaction under Solvent-free Conditions

2020 ◽  
Vol 17 (6) ◽  
pp. 438-442
Author(s):  
Xiaofang Ma ◽  
Shunxi Li ◽  
Samrat Devaramani ◽  
Guohu Zhao ◽  
Daqian Xu
Keyword(s):  
Reaction Time ◽  
Organic Synthesis ◽  
Carbonyl Compounds ◽  
Solvent Free ◽  
Propargyl Bromide ◽  
Important Goal ◽  
One Pot ◽  
Short Reaction Time ◽  
Solvent Free Conditions ◽  
Volatile Organic

The elimination of volatile organic solvents in organic synthesis is the most important goal in “Green” chemistry. We report a simple, efficient and facile method for the addition of progargyl bromide to carbonyl compounds using Mg metal as a mediator under solvent-free conditions which could regioselectively generate homopropargyl alcohols efficiently in good to excellent yields. The procedure has advantages such as short reaction time, operationally simple, excellent product yields, high regioselectivity and organic solvent-free.

Glutamic Acid as an Efficient and Green Catalyst for the One-Pot Synthesis of 1,2,4,5-Tetrasubstituted Imidazoles under Thermal, Solvent-Free Conditions

2017 ◽  
Vol 41 (11) ◽  
pp. 673-675 ◽  
Author(s):  
Fahimeh Khazaee Feizabad ◽  
Khatereh Khandan-Barani ◽  
Alireza Hassanabadi
Keyword(s):  
Glutamic Acid ◽  
Reaction Times ◽  
Catalytic Amount ◽  
Solvent Free ◽  
One Pot ◽  
Green Catalyst ◽  
Aryl Aldehydes ◽  
Solvent Free Conditions ◽  
The One ◽  
Tetrasubstituted Imidazoles

A high-yielding synthesis of 1,2,4,5-tetrasubstituted imidazoles is described, involving the reaction of 1,2-dicarbonyl compounds, aryl aldehydes, amines and ammonium acetate in the presence of a catalytic amount of glutamic acid under thermal, solvent-free conditions. The salient features of this protocol are aerobic conditions, a non-hazardous green catalyst, short reaction times and mild reaction conditions.

scholarly journals CeCl3⋅7H2O/SiO2as an Efficient and Recyclable Catalyst for the Synthesis of Dihydropyrano[3,2-b]chromenediones

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Chong Zhang ◽  
Yan Qu
Keyword(s):  
Kojic Acid ◽  
Aromatic Aldehydes ◽  
Catalytic Amount ◽  
Recyclable Catalyst ◽  
Solvent Free ◽  
One Pot ◽  
Solvent Free Conditions ◽  
Three Component Reaction ◽  
High Yields

Dihydropyrano[3,2-b]chromenedione derivatives were synthesized in moderate-to-high yields in one-pot three-component reaction from the corresponding aromatic aldehydes, kojic acid, and dimedone, in the presence of catalytic amount ofCeCl3⋅7H2O/SiO2as a nontoxic, reusable, inexpensive, and easily available reagent, under solvent-free conditions.

Efficient synthesis of secondary and primary dialkyl α-aminophosphonates catalyzed by tetramethyl-tetra-3,4-pyridinoporphyrazinato copper(II) methyl sulfate under solvent-free conditions

2008 ◽  
Vol 12 (07) ◽  
pp. 849-856 ◽  
Author(s):  
Sara Sobhani ◽  
Elham Safaei ◽  
Mozaffar Asadi ◽  
Fariba Jalili ◽  
Zahra Tashrifi
Keyword(s):  
Ammonium Acetate ◽  
Catalytic Amount ◽  
Solvent Free ◽  
Reusable Catalyst ◽  
Diethyl Phosphite ◽  
Efficient Synthesis ◽  
Methyl Sulfate ◽  
One Pot ◽  
Solvent Free Conditions ◽  
Heterocyclic Aldehydes

An efficient method for the synthesis of secondary and primary dialkyl α-aminophosphonates under solvent-free conditions by one-pot reaction of aldehydes/ketones, amines/ammonium acetate and trialkyl/diethyl phosphite in the presence of a low catalytic amount of [ Cu (3,4-tmtppa)]( MeSO 4)4(0.16 mol%) as a highly stable and reusable catalyst, is described. By this method, aromatic, aliphatic, cyclic and heterocyclic aldehydes, hindered and cage ketones are converted into their corresponding α-aminophosphonates in good to excellent yields.

Highly Efficient Michael Reactions of Nitroolefins by Grinding Means

2019 ◽  
Vol 16 (3) ◽  
pp. 449-457 ◽  
Author(s):  
Dong-Xiao Cui ◽  
Yue-Dan Li ◽  
Jun-Chao Zhu ◽  
Yan-Yan Jia ◽  
Ai-Dong Wen ◽  
...  
Keyword(s):  
Organic Synthesis ◽  
Room Temperature ◽  
Michael Reaction ◽  
Building Blocks ◽  
Solvent Free ◽  
Michael Additions ◽  
Highly Efficient ◽  
Michael Reactions ◽  
Michael Adducts ◽  
Solvent Free Conditions

Aim and Objective: The direct β-functionalization of trans-β-nitroolefins by Michael reaction is regarded as an efficient way to provide precursors for β-functional amines. However, Michael additions by grinding means with solvent-free conditons are rarely reported. We have developed facile access to β-functional nitroalkanes by grinding means under solvent-free conditions. Materials and Methods: From commercially available materials including ethyl 2-nitroacetate, alkyl 2-cyanoacetates and malononitrile, the grinding reactions between these above-mentioned activated methylenecompounds and various trans-β-nitroolefins were performed at room temperature and solvent-free conditions. Results: A highly efficient direct Michael reaction of nitroolefins by simple grinding means has been developed. Various trans-nitrostyrenes were easily converted into corresponding β-functional nitroalkanes in excellent yields within 5~10 min (up to 36 examples). Conclusion: Herein, we have developed a simple and efficient way to β-functional nitroalkanes through Michael reactions by grinding means. The grinding Michael reaction is fast, clean and stable and these Michael adducts could be easily converted into the other amino compounds served as building blocks in organic synthesis.

scholarly journals Trichloroisocyanuric acid, a New and Efficient Catalyst for the Synthesis of 2′- Aminobenzothiazolo-arylmethyl-2-naphthols

2012 ◽  
Vol 9 (4) ◽  
pp. 2424-2428 ◽  
Author(s):  
Limin Yang
Keyword(s):  
Aromatic Aldehydes ◽  
Catalytic Amount ◽  
Solvent Free ◽  
One Pot ◽  
Efficient Catalyst ◽  
One Pot Synthesis ◽  
Solvent Free Conditions ◽  
Three Component Reaction ◽  
Trichloroisocyanuric Acid

An efficient one-pot synthesis of 2′-aminobenzothiazolo-arylmethyl-2-naphthols is described. This involves the three-component reaction ofβ-naphthol, aromatic aldehydes and 2-aminobenzothiazole in the presence of a catalytic amount of trichloroisocyanuric acid under solvent-free conditions.

Microwave-assisted one-pot synthesis of some new furo[2,3-b]quinolines using potassium carbonate under solvent-free conditions

2007 ◽  
Vol 85 (12) ◽  
pp. 1041-1044 ◽  
Author(s):  
M Raghavendra ◽  
Halehatty S. Bhojya Naik ◽  
Bailure S Sherigara
Keyword(s):  
Organic Synthesis ◽  
Potassium Carbonate ◽  
Solvent Free ◽  
High Yield ◽  
One Pot ◽  
Mass Spectral ◽  
H Nmr ◽  
Microwave Assisted ◽  
Solvent Free Conditions ◽  
Microwave Assisted Method

A rapid, solvent-free microwave-assisted method has been developed for the synthesis of novel furo quinolines. The title compounds were achieved by the reaction between corresponding 2-hydroxy-3-formyl-quinolines (1a–1c) with chloroacetamide, ethylchloroacetate, and phenacylbromide in specially designed microwave (MW) oven for organic synthesis in unsealed borosil vessel in presence of potassium carbonate. In this method, isolation is accomplished by just treating the reaction mixture with water, and products were obtained in high yield. Hence, this method was found to be very effective and ecofriendly. The structure of the newly synthesized compounds has been evaluated on the basis of analytical, IR, 1H NMR, and mass spectral data.Key words: furoquinoline, microwave irradiation, potassium carbonate, solvent-free conditions.

scholarly journals One-Pot Synthesis of Benzoxanthenes in Solvent Free Condition using Chloroaluminate Ionic Liquids as Catalyst

2009 ◽  
Vol 5 (1) ◽  
pp. 575-580
Author(s):  
Sugat Kirti ◽  
Dhanraj T. Masram
Keyword(s):  
Ionic Liquid ◽  
Reaction Times ◽  
Catalytic Amount ◽  
Solvent Free ◽  
Imidazolium Chloride ◽  
One Pot ◽  
Free Condition ◽  
Solvent Free Condition ◽  
Solvent Free Conditions ◽  
One Pot Condensation

A mild and efficient method has been developed for the preparation of 14-aryl-14H dibenzo[a,j]xanthenes from one-pot condensation of aldehydes with β-naphthol using catalytic amount of Chloroaluminate ionic liquid (imidazolium chloride·3AlCl3 or pyridiniumchloride·3AlCl3) under thermal solvent-free conditions. Excellent yields, short reaction times, easy workup and reusability of the catalyst as well as solvent free conditions are advantages of this procedure.

Solvent-free Three Component Synthesis of N-alkylated Derivatives of N-Acylhydrazones from Hydrazides, Aldehydes and α,β-unsaturated Esters

2020 ◽  
Vol 17 ◽  
Author(s):  
Gholamhassan Imanzadeh ◽  
Samira Zolfagharzadeh ◽  
Zahra Soltanzadeh
Keyword(s):  
Tetrabutylammonium Bromide ◽  
Side Reaction ◽  
Solvent Free ◽  
Alkyl Derivative ◽  
Organic Salt ◽  
Unsaturated Ester ◽  
One Pot ◽  
Solvent Free Conditions ◽  
Three Component Reaction ◽  
Derivatives Of

Abstract:: A number of new N-alkylated derivatives of N-acylhydrazones have been prepared via one pot three-component reaction between hydrazide, aldehyde, and α,β-unsaturated ester using 1,4-diaza-bicyclo[2,2,2]octane (DABCO), as an in-expensive base and tetrabutylammonium bromide (TBAB), an ionic organic salt media, under solvent-free conditions. In the case of 2-hydroxy benzaldehyde, the reaction proceeds with the exclusive formation of the N-alkyl derivative without any concurrent O-alkylation side reaction.

One-pot Synthesis of Novel Thiophene Containing Aminonaphthols using Fe3O4 Nanoparticles as a Recyclable Heterogeneous Catalyst

2021 ◽  
Vol 10 ◽  
Author(s):  
Ganesh Pavale ◽  
M. M. V. Ramana ◽  
Poornima Acharya ◽  
Sarfaraz Shaikh
Keyword(s):  
Catalytic Activity ◽  
Metal Oxide ◽  
Fe3o4 Nanoparticles ◽  
Metal Oxide Nanoparticles ◽  
Solvent Free ◽  
Precipitation Method ◽  
Synthetic Approach ◽  
One Pot ◽  
Solvent Free Conditions ◽  
Wide Range

Background: Metal oxide and metal oxide nanoparticles are gaining significant importance due to their reusability and wide range of catalytic applications in many organic transformations. Objective: To report simple and efficient Fe3O4 catalyzed one-pot five-component reaction protocol to synthesize novel thiophene containing aminonaphthols under solvent-free conditions. Method: To prepare the Fe3O4 nanoparticles by facile and simple co-precipitation method and surface characterization was done using FT-IR, XRD, BET, SEM, and TEM analysis technique. Aminonaphthol derivatives bearing thiophene moiety were synthesized using Fe3O4 nanoparticles under solvent-free conditions. Results: The prepared nanoparticles are smaller in size (15nm) and can be easily detachable. It can be recycled and reused five times without any significant loss of catalytic activity with excellent yields in a short time. The existing protocol for synthesizing amino naphthol becomes feasible and attractive due to the reusability of the catalyst, excellent catalytic performance, and eco-friendly procedure. Conclusion: In conclusion, Fe3O4 nanoparticles provide a simple, efficient, and greener one-pot five-component synthetic approach to synthesize thiophene containing aminonaphthols. Excellent catalytic activity was perceived in a short reaction time without any co-catalyst or any other activator. Moreover, reusability of catalyst, high yields, and environmentally benign solvent-free condition are vital factors of this protocol.

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