A convenient and highly efficient procedure for the synthesis of 3,4-dihydropyrimidin-2-(1H)-one/thione derivatives via one-pot three-component Biginelli condensation of arylaldehydes,urea/thiourea and ethyl/methyl acetoacetate in the presence of Zn(SO4)2.7H2Oas anefficient, readily and inexpensive catalyst under solvent-free conditions have been studied. Thisprotocol ha...

a mild and efficient method has been developed for the preparation of substituted coumarins from reaction of various phenols with different β-ketoesters via pechmann condensation in the presence of brønsted acidic ionic liquid (n-(4-sulfonic acid) butyl triethylammonium hydrogen sulfate) as an effective catalyst under solvent-free conditions. different phenols reacted with ethyl acetoacetate to...

An Fe group ternary nanoalloy (NA) catalyst enabled selective electrocatalysis towards CO2-free power generation from highly deliverable ethylene glycol (EG). A solid-solution-type FeCoNi NA catalyst supported on carbon was prepared by a two-step reduction method. High-resolution electron microscopy techniques identified atomic-level mixing of constituent elements in the nanoalloy. We examined ...

3-methyl-1-(4-sulfobuthyl)-1-h-imidazol-3ium hydrogen sulfate, as a dual acidic ionic liquid (dail), was found to be an efficient catalyst for the simple, rapid and green synthesis of substituted trisphenols from the condensation of different substituted phenols and 2,6-bis (methylol) phenols (bmp). dail catalyst efficiently promoted the reaction between phenols and bmps with a variety of funct...

a simple and efficient method for the chemoselective 1,1-diacetate protection of aromatic aldehydes with acetic anhydride by using ni2+ supported on hydroxyapatite-core-shell magnetic γ-fe2o3 nanoparticles (γ-fe2o3@hap-ni2+) under solvent free conditions. this method has several advantages, including high yield, short reaction time, simple work-up and recyclable property of the catalyst. the ca...

nano sulfated titania was tested as solid acid heterogeneous catalyst for the synthesis of 4-(trifluoromethyl) coumarin and coumarin derivatives under solvent-free condition. factorial design evidenced a positive effect of reaction temperature, amount of catalyst, and solvents.  this nano-sized sulfated titania has been prepared by a sol-gel hydrothermal process. the prepared sulfated titania s...

We introduce an entirely new method for forming hydrogels, wherein the formation is triggered by a catalyst, but the resulting hydrogels are catalyst-free. We unexpectedly found that a sufficient amount of crosslinkable catecholquinone/semiquinone free radicals is generated by the physical contact between catechol-containing polymers and surface-immobilized catalysts.

A  convenient  and  efficient  one-pot  four-component  synthesis  of  1,  2,  4,  5-tetrasubstituted  imidazoles  using  nano  TiO2  as  a  recyclable  catalyst  is  reported.  The results  show  that  the  methodology  has  several  advantages  such  as  low  loading  of catalyst,  excellent  yield,  short  reaction  time,  operational  simplicity  and  solvent-free conditions.