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
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
A novel PVP-I catalyzed acetalizations/transacetalizations of carbonyl compounds has been developed processing with a mild and easy handling fashion. Different types of Acyclic and cyclic acetals were prepared from carbonyl compounds or their acetals successfully. Further applications of newly developed catalytic combination were testified. This protocol featured with simplicity of operation, mild
MOF-808 as a recyclable catalyst for the photothermal acetalization of aromatic aldehydes
作者:Allison M. Rabon、Jared G. Doremus、Michael C. Young
DOI:10.1016/j.tet.2021.132036
日期:2021.4
their porosity, high internal surface area, and structural adaptability. Typical acetylation reactions of aldehydes require elevated temperatures and excess alcohol to drive the reactions to completion. In this current work, MOF-808 is used as a heterogeneous catalyst for acetylation of aldehydes in methanol using a mild photothermal process. Optimized conditions gave 72% yield of 2-(dimethoxymethyl)naphthalene
Preparation of acetals from aldehydes and alcohols under basic conditions
作者:Jakub Grabowski、Jarosław M. Granda、Janusz Jurczak
DOI:10.1039/c8ob00017d
日期:——
A new, simple protocol for the synthesis of acetalsunder basic conditions from non-enolizable aldehydes and alcohols has been reported. Such reactivity is facilitated by a sodium alkoxide along with a corresponding trifluoroacetate ester, utilizing formation of sodium trifluoroacetate as a driving force for acetalformation. The usefulness of this protocol is demonstrated by its orthogonality with