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.
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
Reversing the Regiochemical Course of 1,3-Dipolar Cycloaddition of Nitrile oxides by Modification of Dipolarophiles
作者:Akio Kamimura、Kenzi Hori
DOI:10.1016/s0040-4020(01)85282-0
日期:1994.1
Cycloaddition to the acetal derivatives preferentially gave the regioisomer bearing acetal group on C(4) position. While the opposite regioselectivity was observed for the cycloaddition to dithioacetal derivatives, where the sulfur functional group was mainly located at C(5) position. Theoretical studies on these regiochemical courses showed the C(5) orientation of dithioacetal groups to be directed
OXIDATIVE COUPLING OF KETENE DITHIOACETALS WITH SILYLATED CARBON NUCLEOPHILES BY THE USE OF TRITYL TETRAFLUOROBORATE
作者:Yukihiko Hashimoto、Teruaki Mukaiyama
DOI:10.1246/cl.1986.755
日期:1986.5.5
2-Alkenyl-1,3-dithiolan or dithian-2-ylium cations are yielded by hydride abstraction of cyclic ketene dithioacetals with trityl tetrafluoroborate. These cations react with silyl enol ethers or an allylsilane completely regioselectively to give the corresponding functionalized ketene dithioacetals.
Highly Efficient Transthioacetalization of O,O-Acetals Catalyzed by Indium(III) Chloride
作者:Brindaban C. Ranu、Arijit Das、Sampak Samanta
DOI:10.1055/s-2002-25347
日期:——
A simple, efficient and general procedure has been developed for the transthioacetalization of O,O-acetals catalyzed by indium(III) chloride in 1,2-dichloroethane.