Sulfamic acid: An efficient, cost-effective and green catalyst for crossed-aldol condensation of ketones with aromatic aldehydes under solvent-free
作者:Amin Rostami、Firoz Ahmad-Jangi
DOI:10.1016/j.cclet.2011.03.015
日期:2011.9
Abstract Aromatic aldehydes undergo crossed-aldol condensation with ketones in the presence of catalytic amount of sulfamic acid (SA) to afford the corresponding α , β -unsaturated aldol products under solvent-free conditions in good to high yields at 45–80 °C.
Addition with α,β unsaturated carbonyl compounds gives 1,5 dicarbonyl products. This method is very convenient and the compounds obtained can easily be separated. We assume that the role of the salt in these reactions is to activate the silicon atom by anionic coordination to form a pentacoordinatedsilicon intermediate.
A Facile Synthesis of α, α'-bis(Substituted Benzylidene)cycloalkanones Catalyzed by bis(<i>p</i>-ethoxyphenyl)telluroxide(bmpto) Under Microwave Irradiation
Abstract The bis(4-methoxyphenyl)telluroxide(BMPTO) catalyzed reaction of cyclopentanone or cyclohexanone with aldehydes brought about the cross-aldol condensation to give the corresponding 2, 5-bis(substitutedbenzylidene) cyclopentanones or 2, 6-bis(substitutedbenzylidene)cyclohexanones in high yield under microwave irradiation in mild conditions. The reaction needs only 5-10 min. #Works in Medical
Sulfuric Acid-modified PEG-6000 (PEG-SO<sub>3</sub>H): An Efficient, Bio-degradable and Reusable Catalyst for Synthesis of &alpha;, &alpha;' bis(arylidene) Cycloalkanones Under Solvent-free Conditions
作者:Mohammad A. Nasseri、Mehri Salimi
DOI:10.2174/1570178611310030004
日期:2013.4.1
A green and efficient method for synthesis of α,α' -bis (arylidene) cycloalkanones, starting from aromatic aldehydes in reaction with ketones using sulfonated polyethylene glycol 6000 (PEG-SO3H) as a stable, reusable and biodegradable catalyst under solvent-free conditions at 80 °C is described. The use of a nontoxic, inexpensive, easily available and recyclable catalyst makes this protocol practical
An efficient green approach to aldol and cross-aldol condensations of ketones with aromatic aldehydes catalyzed by nanometasilica disulfuric acid in water
作者:A. Nakhaei、A. Morsali、A. Davoodnia
DOI:10.1134/s1070363217050292
日期:2017.5
Aldol and cross-aldol condensations of aromaticaldehydes with various ketones in the presence of nanometasilica disulfuric acid (NMSDSA) as heterogeneous catalyst are presented. The catalyst was prepared according to the developed earlier method using inexpensive and readily available starting materials. The highly active catalyst gave excellent yields of the desired aldol products without self-condensation