A Novel Approach to the Practical Synthesis of Sulfides: An InBr<sub>3</sub>-Et<sub>3</sub>SiH Catalytic System Promoted the Direct Reductive Sulfidation of Acetals with Disulfides
Efficient acetalisation of aldehydes catalyzed by titanium tetrachloride in a basic medium
作者:Angelo Clerici、Nadia Pastori、Ombretta Porta
DOI:10.1016/s0040-4020(98)00982-x
日期:1998.12
The acetalisation of aliphatic and aromatic aldehydes is achieved in a basic medium by using catalytic amount of Ti(IV) chloride in MeOH in the presence of NH3 or Et3N. The present protocol shows many advantages over the well known base or acid catalysis: in fact, in contrast to base-promoted acetalisation, aldehydes with electron-rich carbonyl groups react easily, enolizable aldehydes do not undergo
Transdithioacetalization of acetals, ketals, oximes, enamines and tosylhydrazones catalysed by natural kaolinitic clay
作者:G. K. Jnaneshwara、N. B. Barhate、A. Sudalai、V. H. Deshpande、R. D. Wakharkar、A. S. Gajare、M. S. Shingare、R. Sukumar
DOI:10.1039/a706475f
日期:——
Natural kaolinitic clay efficiently catalyses the transdithioacetalization of acetals, ketals, oximes, enamines and tosylhydrazones with ethane-1,2-dithiol and propane-1,3-dithiol to produce the corresponding dithiolanes in high yields.
Acid-Catalyzed Conversion of Xylose in Methanol-Rich Medium as Part of Biorefinery
作者:Xun Hu、Caroline Lievens、Chun-Zhu Li
DOI:10.1002/cssc.201100745
日期:2012.8
treatments of xylose have been performed in a methanol/water mixture to investigate the reaction pathways of xylose during bio‐oil esterification. Xylose was mainly converted into methyl xylosides with negligible humins formed below 130 °C. However, humins formation became significant with the dehydration of xylose to furfural and 2‐(dimethoxymethyl)furan (DOF) at elevated temperatures. The conversion of xylose
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