Organic Communications Articles

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.

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.

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.

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.

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.

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.

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.

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.