Zolfigol, Mohammad Ali, Yarie, Meysam, Baghery, Saeed, Khoshnood, Abbas, Alonso, Diego A.
1H-imidazol-3-ium tricyanomethanide {[HIM]C(CN)3} as a nanostructured molten salt catalyst: application to the synthesis of pyrano[4,3‐b]pyrans
Research on Chemical Intermediates. 2017, 43(5): 3291-3305. doi:10.1007/s11164-016-2826-y
URI: http://hdl.handle.net/10045/66495
DOI: 10.1007/s11164-016-2826-y
ISSN: 0922-6168 (Print)
Abstract: 
In this work, we have synthesized a novel nanostructured molten salt, 1H-imidazol-3-ium tricyanomethanide {[HIMI]C(CN)3} (1), as an efficient and green protocol-compatible catalyst. This new molten salt has been fully characterized by different analytical techniques, such as FT-IR, 1HNMR, 13CNMR, thermal gravimetric analysis, derivative thermal gravimetric analysis, differential thermal analysis, X-ray diffraction, scanning electron microscopy, and high-resolution transmission electron microscopy. Additionally, the catalytic activity of {[HIMI]C(CN)3} (1, 2 mol%) has been tested in a three-component domino Knoevenagel condensation reaction. A range of structurally diverse aromatic aldehydes (2a–p), malononitrile (3), and 4‐hydroxy‐6‐methyl‐2H‐pyran‐2‐one (4) are tolerated for the synthesis of 2-amino-7-methyl-5-oxo-4-aryl-4,5-dihydropyrano[4,3-b]pyran-3-carbonitrile derivatives (5a–p) under neat conditions at 50 °C. The obtained results have demonstrated that catalyst 1 shows interesting catalytic properties, such as clean reaction profile, cost-effectiveness, and green conditions. Importantly, the aforementioned catalyst is thermally stable with a 171 °C melting point not showing any significant loss in catalytic activity after 7 reaction cycles.
Keywords:Multicomponent reactions, Knoevenagel condensation, Nanostructured molten salt, Neat conditions, Green chemistry
Springer Science+Business Media Dordrecht
info:eu-repo/semantics/article