Molten Salt as a Green Reaction Medium: Efficient and Chemoselective Dithioacetalization and Oxathioacetalization of Aldehydes Mediated by Molten Tetrabutylammonium Bromide
作者:Brindaban C. Ranu、Arijit Das
DOI:10.1071/ch03318
日期:——
Tetrabutylammonium bromide in the molten state has been demonstrated to be a very efficient catalyst and reaction medium for the highly chemoselective dithioacetalization and oxathioacetalization of aldehydes. The tetrabutylammonium bromide is recycled for subsequent reactions.
Perchloric Acid Adsorbed on Silica Gel (HClO<sub>4</sub>-SiO<sub>2</sub>) as an Extremely Efficient and Reusable Catalyst for 1,3-Dithiolane/Dithiane Formation
作者:Asit Chakraborti、Santosh Rudrawar、Ram Besra
DOI:10.1055/s-2006-942474
日期:2006.8
Perchloric acid adsorbed on silicagel (HClO 4 -SiO 2 ) has been found to be an extremely efficient and reusable catalyst for 1,3-dithiolane and 1,3-dithiane formation under solvent-free conditions at room temperature.
Solvent Free Thioacetalization of Carbonyl Compounds Catalyzed by Cu(OTf)<sub>2</sub>-SiO<sub>2</sub>
作者:R. Vijaya Anand、P. Saravanan、Vinod K. Singh
DOI:10.1055/s-1999-2635
日期:1999.4
Aldehydes and ketones were thioacetalyzed using 1,2-ethanedithiol in the presence of a catalytic amount of Cu(OTf)2-SiO2 under solvent free conditions in excellent yields.
Copper(II) tetrafluoroborate as an extremely efficient catalyst for 1,3-dithiolane/dithiane formation from carbonyl compounds under solvent-free conditions at room temperature
作者:Ram C. Besra、Santosh Rudrawar、Asit K. Chakraborti
DOI:10.1016/j.tetlet.2005.07.059
日期:2005.9
formation from aromatic, heteroaromatic and aliphatic aldehydes and cyclic saturated ketones in 1–5 min under solvent-free conditions at room temperature. The reaction is compatible with other functionalities such as ether, ester, hydroxyl, halide, nitro and cyano groups and exhibits excellent chemoselectivity. α,β-Unsaturated aldehydes/ketones lead to selective formation of 1,3-dithiolanes instead of
Chemoselective thioacetalisation and transthioacetalisation of carbonyl compounds catalysed by tetrabutylammonium tribromide (TBATB)Dedicated to Professor Subramanian Ranganathan on the occasion of his 70th birthday.
作者:Sarala Naik、Rangam Gopinath、Mousumi Goswami、Bhisma K. Patel
DOI:10.1039/b402648a
日期:——
Thioacetals and thioketals of various aldehydes and ketones were obtained directly from carbonylcompounds or by a transthioacetalisation process from cyclic O,O-acetals in the presence of dithiols and a catalytic amount of tetrabutylammonium tribromide (TBATB). Chemoselective thioacetalisation of aromatic aldehydes containing an electron-donating group in the presence of an aldehyde containing an