For the first time B-podands have been studied as an efficient and powerful catalysts in the ring opening of epoxides with azide anion in water. The reaction afforded the corresponding 1,2-azidoalcohols with high regioselectivity under mild reaction conditions and in a highly atom economic fashion.
A convenient, efficient and practical procedure for the synthesis of 1-amidoalkyl 2-naphthols is described by condensation of aromatic aldehydes with amides and 2-naphthol in the presence of P2O5/SiO2 as an efficient catalyst. Moreover, in the present of this catalyst, the synthesis of 14-aryl or alkyl-14H-dibenzo[a,j]xanthenes is studied by condensation of aldehydes with 2-naphthol. Using solvent-free […]
Two simple protocols for the synthesis of three-component condensation reaction of an aldehyde, β-ketoester and urea or thiourea to obtain the 3, 4-dihydropyrimidin-2(1H)-ones (thiones) using nano silica phosphoric acid are reported. Short reaction times, high yields, reusability of catalyst and easy workup are some advantages of these protocols.
A simple and mild method for tetrahydropyranylation of alcohols is reported at room temperature using a catalytic amount of 3-methylimidazolinium hydrogensulfate([Hmim]HSO4) as a green, efficient and reusable catalyst. Using solvent-free conditions, non-toxic and inexpensive materials, modest and clean work-up, short reaction times and high yields of the products are the advantages of this method.
An efficient green route for the preparation of naphthoxazinones, applying a three-component one-pot condensation reaction of 2-naphthol, aromatic aldehyde and urea in the presence of nano silica supported ferric chloride under solvent-free conditions has been developed. The present procedure offers several advantages such as short reaction time, simple workup, recovery and reusability of the catalyst.
P2O5-SiO2 (30% w/w) was found to be a useful catalyst for the synthesis of various 2-substituted aryl benzimidazoles under solvent-less and in solvent conditions from o-phenylenediamine and aldehydes. The products were directly recrystallized from methanol.
In our current study, supercritical water impregnation (SCWI) was introduced as a unique catalyst preparation method by employing the high diffusivity property of supercritical water. The method allows nano-particles to place on support surfaces in extremely dispersed conditions. The silica-based nanocatalyst granules for this purpose were prepared by initial impregnation of highly porous silica (500 […]
Sulfonated polystyrene/montmorillonite nanocomposite (OMMT/PS-SO3H) was prepared and used as a novel, efficient and inexpensive heterogeneous acid catalyst in the one-pot reaction three-component Mannich reaction of ketones, aromatic aldehydes and amines under solvent-free conditions. The catalyst was characterized by XRD, SEM, TG, BET and FT-IR techniques. This method has advantages of high yield, moderate to excellent […]