The reactions of 2-perfluoroacyl-1H-benzo[f]chromenes and 6,7-dimethyl-3-trifluoroacetyl-4H-chromene with primary aliphatic amines ammonia afforded a series enamino ketones containing (2-hydroxynaphthalen-1-yl)methyl or 2-hydroxybenzyl substituent in the ?-position respect to carbonyl group. These involved opening pyran ring, which followed aza-Michael addition as initial step. obtained were fo...

Some chromeno[4′,3′-b]pyrano[6,5-b]quinoline derivatives were synthesized by condensation of 2-amino-4-aryl-3-cyano-5-oxo-4H, 5H -pyrano-[3,2-c] chromenes and 1,3-cyclohexanedione in an environmentally benign and efficient method by Cu(II)-Schiff base/SBA-15 as an environmentally friendly heterogeneous and recyclable catalyst under solvent-free conditions in high yields and rates. These kinds o...

An efficient and eco-friendly protocol for the preparation of 2-amino-4H-chromenes employing a multi-component, one-pot condensation reaction between aromatic aldehydes, malononitrile and1-naphthol has been developed. The reaction of 1-naphthol with malononitrile and various aromatic aldehydes was carried out i...

In the present work, bakers yeast catalyzed efficient synthesis of 2-amino-2-chromenes in methanol is presented. Here ultrasonication has dual role i.e. as a source energy for reaction and tool disruption cells. The cyclocondensation been essentially carried under neutral conditions, thus reducing possibility unwanted side reactions.

The treatment of β,γ-unsaturated α-ketoesters with phenols in the presence of trityl chloride and 4 Å molecular sieves in refluxing trifluoroacetic acid afforded 4-aryl-2H-chromenes in high yields, in which a reverse of the regiochemistry of Jørgensen-Rutjes chromane synthesis was observed. The isolation of 4H-chromene intermediates, confirmed by single-crystal X-ray analysis, indicates that th...