Caffeine-based Acidic catalysts for the one-pot preparation of Some Multi- Component Reactions

Multi-component reactions (MCRs), has been in the focus of concern recently by organic and medicinal chemists, due to the simplicity and the diversity these reactions provide. Apart from their applications in synthesis, MCRs have been utilized as a criteria for benchmarking novel catalysts. Caffeine-based acidic catalysts including caffeine-H2SO4, and caffeine-H3PO4 has been prepared and applied for the One-pot preparation of Bis(indolyl) methanes, 4, 4′- (arylmethylene) bis (1H-pyrazol-5-ols), 3,3 -(arylmethylene) bis (4-hydroxycoumarins), 2,4,5-Tri-substituted imidazoles, 1‐amidoalkyl‐2‐naphthols, and Polyhydroquinolines. The Catalysts were characterized with FTIR, 1HNMR, 13CNMR, TGA, XRD and LC-Mass spectroscopy. According to the obtained results, including high yield of the products, short reaction Time, facile separation of the catalyst and easy work-up procedure, Caffeine-based catalysts can be considered as an efficient acidic catalyst for organic transformations [1, 2] (Scheme 1).