Organic Communications Articles
Issue: 2 April-June
Year: 2012 Volume: 5 Issue:2 April-June
1) Iminium salt mediated nitro decarboxylation of α, β-unsaturated acids for the synthesis of β–nitro styrenes under non–conventional conditions
Iminium Salt Mediated Nitro decarboxylation of alpha,beta Unsaturated Acids has been taken up under conventional and non – conventional conditions. Vilsmeier - Haack (VH) Reagent is used as a source for the generation of iminium salt. Equimolar mixture of either DMF/SOCl2 or DMF/POCl3 is used for the preparation of VH reagent. Reactions afforded good yield of products under conventional conditions with longer reaction times. Microwave irradiated reactions not only reduced the reaction times but enhanced the yield of products from good to excellent.DOI Keywords Nitration α, β-unsaturated acids vilsmeier-haack (VH) reagent solvent- free microwave. DETAILS PDF OF ARTICLE © 2012 ACG Publications. All rights reserved.
2) Green chemical synthesis of α-hydroxyphosphonates
A green and efficient method for the preparation of α-hydroxyphosphonates (3a-n) in minutes of time with high yields is accomplished by grinding the mixture of various aldehydes (1a-n) and diethylphosphite (2) at room temperature under solvent free conditions in presence of piperazine as catalyst.Keywords α-Hydroxyphosphonates piperazine grinding diethylphosphite green process. DETAILS PDF OF ARTICLE © 2012 ACG Publications. All rights reserved.
3) Synthesis of benzyl chlorides and cycloveratrylene macrocycles using benzylic alcohols under homogeneous catalysis by HCl/dioxane
The synthesis of benzyl chlorides, cyclic derivatives cyclotriveratrylene and cyclotripiperotrylene were carried out in using the HCl/dioxane system as a catalyst. The reaction proceeded with high selectivity and is sensitive to the number of alkyl and methoxy substituent on the aromatic ring.Keywords Benzyl alcohols veratrole alcohol benzyl chlorides cyclotripiperotrylene cyclotriveratrylene. DETAILS PDF OF ARTICLE © 2012 ACG Publications. All rights reserved.
4) Solvent-free methodologies for organic brominations using quaternary ammonium tribromides
The efficacies of different organic ammonium tribromides were studied with different classes of organic substrates using solvent-free reaction protocols involving reactions at elevated temperature and also under microwave conditions. The reactions were regio-selective, facile and afforded good to excellent product yields in short reaction time.Keywords Quaternaryammonium tribromide (QATB) thermal condition microwave bromination comparative study DETAILS PDF OF ARTICLE © 2012 ACG Publications. All rights reserved.
5) Iodine-catalyzed addition of 2-mercaptoethanol to chalcone derivatives: Synthesis of the novel β-mercapto carbonyl compounds
In this study, a series of novel β-mercapto carbonyl derivatives (3-(2-hydroxyethylthio)-1,3- diarylpropan-1-one) (5a-i) were prepared by addition of 2-mercaptoethanol (4) to chalcones (3a-i) in the presence of catalytic amount of iodine (10 mol %) in CH2Cl2.Keywords Chalcone 2-mercaptoethanol iodine Thia-michael addition β-mercapto carbonyl. DETAILS PDF OF ARTICLE © 2012 ACG Publications. All rights reserved.
6) A chiral 1,3,2-dioxaborolane derived from a natural diterpene for asymmetric reduction of prochiral ketones
The application of a chiral 1,3,2-dioxaborolane, for the sulfide complex-mediated asymmetric reduction of prochiral ketones at room temperature, are described. The B-methoxy-dioxaborolane was synthesized from 2α,3α-dihydroxycativic acid, a labdane-type diterpene isolated from aerial parts of Baccharis scandens DC. Very good chemical yields (85-97%) and high enantioselectivities (62-96% ee), were obtained.Keywords Asymmetric reductions chiral 1 3 2-dioxaborolane 2α 3α-dihydroxycativic acid. DETAILS PDF OF ARTICLE © 2012 ACG Publications. All rights reserved.
7) Synthesis and antimicrobial screening of novel 2-(5-(4-(allyloxy)- 3-methoxyphenyl)-1H-pyrazol-3-yl)phenols analogues of 2-(4- (allyloxy)-3-methoxyphenyl)-4H-chromen-4-ones
A series of novel 2-(5-(4-(allyloxy)-3-methoxyphenyl)-1H-pyrazol-3-yl)phenols derivatives have been synthesized via the ring opening of 2-(4-(allyloxy)-3-methoxyphenyl)-4H-chromen-4-ones in ethanol and hydrazine hydrate under reflux condition. The synthesized compounds were screened for antibacterial and antifungal activity against bacteria Staphylococcus aureus (MRSA E710) and Escherichia coli (ATCC 25922) and fungi Candida albicans and Aspergillus fumigates respectively. Some of the tested compounds showed significant antimicrobial activity. 1H NMR, IR, Mass spectral data and elemental analysis elucidated the structures of the all newly synthesized compounds.Keywords Pyrazoles chromones chalcones antimicrobial activity. DETAILS PDF OF ARTICLE © 2012 ACG Publications. All rights reserved.
8) Solvent-free and room temperature synthesis of thiochromans in the presence of a catalytic amount of iodine
Iodine catalyzed cyclocondensation of α, β-unsaturated aldehydes with arenethiols afford the corresponding 2-substituted-4-(arylthio)thiochromans in good yield under solvent-free and room temperature conditions. The present protocol offers advantages over the conventional methods reported using mineral acids in terms of reaction time, easy work up and mild conditions.Keywords Thiochromans α β-unsaturated aldehydes arenethiols iodine solvent-free room temperature. DETAILS PDF OF ARTICLE © 2012 ACG Publications. All rights reserved.