Search

A facile, efficient and eco‐friendly catalytic protocol was developed for the synthesis of medicinally important pyran‐annulated heterocycles via multicomponent reaction (MCR). Cyclocondensation of differently substituted aromatic aldehydes, malononitrile/ethyl cyanoacetate and various β‐dicarbonyl compounds in the presence of Ag3[PMo12O40]⋅nH2O as heterogeneous catalyst, in EtOH–H2O, afforded diverse pyran‐fused chromene analogues. The merits observed for this approach were it being conducted via MCR, using commercially available or easily accessible starting materials in the presence of a green and easily separable heterogeneous and reusable catalyst, and affording high yields of desired products in very short reaction times with high purity in one‐pot fashion, thus providing a superior alternative approach for the synthesis of pyran‐annulated heterocycles. [ABSTRACT FROM AUTHOR]

A novel one-pot, five-component reaction for the synthesis of highly functionalized pyranopyrazoles from acid chlorides, Meldrum's acid, hydrazine hydrate, aromatic aldehydes and malononitrile in the presence of catalytic amount of CuI nanoparticles in aqueous media is reported. This method provides several benefits such as in situ preparation of β-ketoester, mild reaction conditions, and environmentally friendly, waste-free and simple work-up procedure with excellent yields. The catalyst could be recovered and reused for several times with almost consistent catalytic activity. [ABSTRACT FROM AUTHOR]