Effect of nanosized TiO2–SiO2 covalently modified by chiral molecules on the asymmetric Biginelli reaction

Recent Advances in Homogeneous and Heterogeneous Catalyst in Biginelli Reaction from 2015‐19: A Concise Review

“…The model reaction performed between 1 (10 mmol), 3 ( 10 mmol) and 5 (10 mmol) in the presence of (1) chiral catalysts (10 mol %) as shown in Figure ,10 mol % of chiral catalyst+TiO 2 ‐SiO 2 (70 mg,1 mmol ) (3) 10 mol % of immobilized catalyst . First in all the reaction, 1 , 3 & chiral catalyst are added in the THF and stirred for 30 min.…”

A Greener and Facile Synthesis of Imidazole and Dihydropyrimidine Derivatives under Solvent‐Free Condition Using Nature‐Derived Catalyst

“…In spite of the availability of numerous synthetic methodologies, most of these techniques involved the use of expensive chemicals, air sensitive catalysts, special efforts for the preparation of the starting materials and use of toxic organic solvents etc. Keeping in view the philosophy of chemical research that encourages the design of products without the use of hazardous substances, researchers switched to other unique and efficient acid catalyst such as (‐)‐Ptilomycalin A, clays, ionic liquids, animal bones, natural phosphates etc . Practically, these catalysts are cheap, easily available, easy to prepare, safe to handle and above all environmentally favorable towards greener approach.…”

An efficient green protocol for the preparation of acetoacetamides and application of the methodology to a one-pot synthesis of Biginelli dihydropyrimidines. Expansion of dihydropyrimidine topological chemical space

“…1 One of these multi-component reactions is the Biginelli reaction, 2 the mechanism of which continues to generate debate as it is highly reaction condition dependent. 14 Recent examples of enantioselective DHPM synthesis include the use of chiral covalently modified nanocomposites, 15 double axially chiral bis-phosphorylimides, 16 is limited. 2, 3g, 13 Numerous synthetic methodologies have been devised that have principally focused upon reaction efficiency as a function of catalyst and reaction conditions 2i and more recently it has been recognized that the DHPM scaffold is a highly functionalized substrate that can be readily applied to postcondensation transformations.…”