in this work, a green, simple and highly efficient procedure for the synthesis of bis(indolyl)methanes is described. the condensation of indoles with carbonyl compounds catalyzed by citric acid in water affords bis(indolyl)methanes in high yields and relatively short reaction times. the advantages of this method are using of water as a low cost solvent and efficient recyclability of the catalyst.

2,2'-Disubstitutedamino-4-4'-bis-pyrimidines (3a-m) have been prepared by linking 2,4-dichloro-6-methyl-5-nitropyrimidine (1) with several diamines and subsequent reaction with suitable amines. Some of these compounds (3c and 3j) which were reduced catalitically, on treatment with nitrous acid, urea in pyridine, and boiling thionyl chloride gave the corresponding bistriazolopyrimidin (6), ...

Nitrile oxide 1,3 dipolar cycloaddition is a simple and powerful coupling methodology. However, the self-dimerization of nitrile oxides has prevented the widespread use of this strategy for macromolecular coupling. By combining an in situ nitrile oxide generation with a highly reactive activated dipolarophile, we have overcome these obstacles and present a metal-free macromolecular coupling str...

Simple haloaldehydes, including enolisable aldehydes, were found to be suitable for the formation of cyclic products by cascade (domino) condensation, cyclisation, dipolar cycloaddition chemistry. This multi-component reaction approach to heterocyclic compounds was explored by using hydroxylamine, a selection of aldehydes, and a selection of activated dipolarophiles. Initial condensation gives ...

in the present study, aqueous solutions of some copper-complexing ligands were screened for their cytotoxicity using brine shrimp lethality test. among the ligands tested, diacetyl-bis(n4-methylthiosemicarbazones) (atsm) proved to be the most safe and non-toxic compound (2% lethality at 10 ppm), while pyruvaldehyde bis(n4-methyl)thiosemicarbazone (ptsm) was shown to possess low toxicity (7% let...

Chiral nonracemic aminated nitroso acetals were synthesized via diastereoselective multicomponent [4 + 2]/[3 + 2] cycloadditions employing new (S,E)-γ-nitrogenated nitroalkenes 5a-c as heterodienes, ethyl vinyl ether (EVE) as a dienophile, and selected electron-deficient alkenes as 1,3-dipolarophiles. The employment of different organic solutions of LiClO4 or LiCl as promoter systems provided t...

Methionine, S-benzylcysteine and S-allylcysteine were converted into 2-diazo-3-oxo-4-phthalimidocarboxylic esters 8a-c in three steps. Upon rhodium-catalysed dediazoniation, two intramolecular carbenoid reactions competed, namely the formation of a cyclic sulfonium ylide and that of a six-ring carbonyl ylide. The S-methyl and S-benzyl ylides 12a and b could be isolated, while S-allyl ylide 12c ...