In recent years, several methods and developments have been reported for the synthesis of pyran and pyridine [13][14][15][16][17] derivatives; each has its own merits and drawbacks. Many of the standard procedures require long reaction times, harsh reaction conditions, expensive and toxic reagents, solvents, and tedious work-up procedures. Moreover in some cases, a mixture of products is obtained, needing cost-effective column chromatography, naturally resulting in low yields. Heterogeneous catalysis is of supreme importance in many areas of the chemical and energy consuming industries [18,19].Conducting the reactions, using heterogenous catalysts should compensate some of drawbacks observed in previously reported reactions. In this kind of reaction, the catalyst can be separated by filtration. However, it is worthy to mention in spite of several advantages, experienced, practically in using of heterogenous catalysts, due to the nanosized particles used, few limitations to the sustainability are observed [20].To get around these problems, the use of a heterogeneous catalyst which can be separated practically other than filtration is desirable. Magnetite nanoparticles (Fe 3 O 4 ) have attracted much attention in the past decade, due to their unique features, including, low preparation cost, high thermal and mechanical stability, and adaptability for largescale production. In addition, their paramagnetic nature allows their facile and effective separation from the reaction mixture, without using standard filtration, required in separation of heterogeneous catalysts. Magnetite nanoparticles (Fe 3 O 4 ) can be easily separated from reaction mixture by using just an external magnet [21].Thus, in recent years, nano-Fe 3 O 4 [22] has attracted a great attention as heterogeneous catalyst [23] due to its simple handling, easy of recovery with an external magnetic field [24,25]. Magnetic nanoparticles (MNPs) have Abstract An atom-economical, efficient and mild protocol is described for the synthesis of 2-amino-3-cyanopyridine and 2-amino-3-cyano-4H-pyran derivatives in the presence of high surface area Fe 3 O 4 as a highly effective heterogeneous catalyst via one-pot multicomponent cyclocondensation reaction.
