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An unprecedented and efficient methodology for the synthesis of 2,4-dichloro-substituted pyrano[2,3-d]pyrimidines and 2,4-dichloro-substituted furo[2,3-d]-pyrimidines is conducted through the one-pot heterocyclization and four-component condensation of acetophenone derivatives, various aromatic aldehydes/potassium iodide, malononitrile, and carbon tetrachloride. The cerium(IV) ammonium nitrate (CAN) was used as a single electron oxidant and ionic liquid (HTPB) as a green promoter under mild conditions at ambient temperature for synthesizing pyrimidine derivatives in high yields. A possible radical mechanism is proposed for these transformations. CAN is found to play an essential role in each step of the reaction. The major advantages of this methodology are experimentally simplicity, environmentally benign, nontoxic, and inexpensive catalyst, excellent yields, and short reaction times. [ABSTRACT FROM AUTHOR]

The aim of this research is the study of hexyltriphenylphosphonium bromide (HTPB) ionic liquid as a bifunctional promoter (solvent and catalyst) in the presence of cerium(IV) ammonium nitrate as a single electron oxidant for the Michael reaction at room temperature and solvent-free conditions. A novel, one-pot and environmentally benign the process to achieve the chemoselective of 2-(3-oxo-1,3-diarylpropyl)malononitrile derivatives instead of 2-(1,3-diarylallylidene)malononitriles using a three-component reaction involving acetophenone derivatives, various aromatic aldehydes and malononitrile was developed. This protocol is simple and provides biologically interesting products in good yields, short reaction times at ambient conditions without the need for using volatile solvents. The remarkable feature of this method is the chemoselectivity of its which makes this protocol effective and distinctive. [ABSTRACT FROM AUTHOR]

A new and simple method for synthesizing iodohydrins and iodoethers from aromatic alkenes is described. Iodohydrins and iodoether derivatives were prepared in excellent yield using Mercury(II) tetrafluoroborate (Hg(BF4)2.SiO2)/I2 in aqueous THF or alcohols (methanol, iso-propanol and tert-butanol). The reactions take place at room temperature, short reaction times, and high regioselectivity, following Markovnikov fashion. [ABSTRACT FROM AUTHOR]

A new and simple method for synthesizing iodohydrins and iodoethers from aromatic alkenes is described. Iodohydrins and iodoether derivatives were prepared in excellent yield using Mercury(II) tetrafluoroborate (Hg(BF4)2.SiO2)/I2 in aqueous THF or alcohols (methanol, iso-propanol and tert-butanol). The reactions take place at room temperature, short reaction times, and high regioselectivity, following Markovnikov fashion. [ABSTRACT FROM AUTHOR]