Vegetable oil as a highly effective 100% bio-based alternative solvent for the one-pot multicomponent Biginelli reaction

Multicomponent one-pot Biginelli reactions have been successfully performed using vegetable oil as bio-based, non-toxic, and environmentally friendly solvents. Palm oil was demonstrated to be a highly effective greener solvent as...

Recent Advances in Biginelli-type Reactions

The effective and high yielding synthesis of poly-functionalized pyrimidines, using multicomponent reactions (MCRs), is imperative in organic and medicinal chemistry. The classic Biginelli reaction is a typically one-pot three-component cyclocondensation reaction involving an aldehyde, a β-ketoester and urea, resulting in the construction of multi-functionalized 3,4-dihydropyrimidin-2(1H)-ones (DHPMs). In recent years, other active methylene compounds, various derivatives of urea and diversely substituted aldehydes have also been used, resulting in the preparation of a new series of various novel dihydropyrimidinones via the Biginelli-Type Reactions (BTRs) or modified Biginelli reactions (MBRs). In this review, we try to underscore the recent advances in BTRs or MBRs.

Ultrasonic Assisted Hydrothermal Synthesis of NiO Nanocatalyst for Low Temperature 3,4-dihydropyrimidin-2-(1H)-Ones and Thiones Condensation Under Solvent-Free Conditions

Present work reports one step hydrothermal method as a green processto synthesizenickel (II) oxide (NiO) nanoparticles using nickel nitrate, and some natural essences as surfactant including Orange blossom, Yarrow, Hibiscus tea, Green tea, Rosemary and Barberryas at 80 ºC in autoclave for 24 h followed by calcination at 700 ºC for 8 h. Rietveld analysis data revealed that the obtained NiO nanomaterials were crystallized in a pure cubic crystalsystem. Field emission scanning electron microscope (FESEM) images showed that the morphology of the obtained materials was changed from non-homogeneous particles to homogeneous spherical particles when the surfactant type was changed from Orange blossom to Barberryas. Catalytic activity of the nanomaterials was investigated in Biginelli reactions for the synthesis of heterocyclic 3,4-dihydropyrimidin-2(1H)-ones (DHPMs) compounds. The synthesis yields at optimum conditions (60 mg of catalyst, 90 ºC reaction temperature and 90 min reaction time) were 94% and 97% for S1 and S6, respectively. Langmuir–Hinshelwood kinetic model revealed that the reactions followed a pseudo-first order kinetic model.