Copper(II) tetrafluoroborate as a novel and highly efficient catalyst for acetal formation
作者:Raj Kumar、Asit K. Chakraborti
DOI:10.1016/j.tetlet.2005.09.168
日期:2005.11
Commercially available copper(II) tetrafluoroborate hydrate has been found to be a highly efficient catalyst for dimethyl/diethyl acetal formation in high yields from aldehydes and ketones by reaction with trimethyl/triethyl orthoformate at room temperature and in short period. Acetalisation was carried out under solvent-free conditions with electrophilic aldehydes/ketones. For weakly electrophilic
Perchloric Acid Adsorbed on Silica Gel (HClO<sub>4</sub>-SiO<sub>2</sub>) as an Inexpensive, Extremely Efficient, and Reusable Dual Catalyst System for Acetal/Ketal Formation and Their Deprotection to Aldehydes/Ketones
作者:Asit Chakraborti、Raj Kumar、Dinesh Kumar
DOI:10.1055/s-2006-958948
日期:2007.1
Perchloric acid adsorbed on silicagel (HClO 4 -SiO 2 ) is reported as extremely efficient, inexpensive, and reusable catalyst for dual role for protection of aldehydes/ketones (with trialkyl orthoformates) as acetals/ketals and deprotection (with water-alcohol) to regenerate the carbonyl compounds in high yields at room temperature and in short times. Acetalization/ketalization of electrophilic aldehydes/ketones
Ruthenium(III) chloride-catalyzed chemoselective synthesis of acetals from aldehydes
作者:Surya K. De、Richard A. Gibbs
DOI:10.1016/j.tetlet.2004.09.060
日期:2004.10
A mild and chemoselective acetalization procedure for the protection of various aldehydes in the presence of ketones is described. (C) 2004 Elsevier Ltd. All rights reserved.
Tetrafluoroboric Acid Adsorbed on Silica Gel as a Reusable Heterogeneous Dual-Purpose Catalyst for Conversion of Aldehydes/Ketones into Acetals/Ketals and Back Again
作者:Asit Chakraborti、Dinesh Kumar、Raj Kumar
DOI:10.1055/s-2008-1042940
日期:2008.4
hydes/ketones are regenerated from the corresponding acetals/ ketals in high yields by the treatment with water-alcohol in the pres- ence of HBF4-SiO2 at room temperature for short times. Excellent selectivity was observed during inter- and intramolecular competi- tion studies involving carbonyl substrates with varying electronic and steric environments. Selective acetalformation of benzalde- hyde takes