Sequence Selective.

The alternate synthesis of indeno-pyridine and indeno-pyran derivatives have been described by an unprecedented, green, of aromatic aldehydes, malononitrile, and indane 1,3-dione. The formation of either indeno-pyridine or indeno-pyran derivatives based on a precise change in the of indane 1,3-dione or malononitrile on Knoevenagel product during the progress of reaction has been investigated. The reaction completed up to 30 min of time using CuO nanoparticles in water at an ambient temperature renders the protocol novel and environment friendly. All the synthesized compounds have been confirmed on the basis of their spectroscopic data. The CuO nanoparticles have been prepared by coprecipitation method and characterized by SEM, PXRD spectroscopy, and UV spectroscopy. [ABSTRACT FROM AUTHOR]