摘要 二硫缩醛化是一类众所周知的有机转化,通过 1,2-乙二硫醇/或 1 来保护多种芳香族化合物(具有释放电子和吸电子取代基)、杂芳香族和脂肪族醛以及酮。 ,3-丙二硫醇在 Fe 3 O 4 @MCM-41-GPTMS-Gu-Cu II NP存在下。在 Fe 3 O 4 @MCM-41-GPTMS-Gu-Cu II存在下化学选择性地获得了相应的 1,3-二硫杂环己烷和 1,3-二噻烷纳米颗粒具有六方核壳结构、超顺磁性,在温和的反应条件下平均粒径为8-25 nm。使用磁棒可以轻松地将纳米结构催化剂从反应混合物中分离出来,并在多次反应中重复使用,而不会显着降低其催化活性。接近中性的条件、良好至高的产物收率、操作简单、后处理程序容易、与各种官能团的相容性使得本方法除了已知的方法之外还有价值。
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.
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
An atom-economical diastereoselective synthesis of indenodithiepines and indenodithiocines has been developed via a domino reaction of propargylicalcohols and dithioacetals in the presence of InCl3 as a catalyst. A range of functionalized dithiepines and dithiocines, fused to the indene ring, were obtained in good to excellent yields under mild conditions.
Silica Gel-Supported Polyphosphoric Acid (PPA/SiO<sub>2</sub>) as an Efficient and Reusable Catalyst for Conversion of Carbonyl Compounds into Oxathioacetals and Dithioacetals
作者:Tadashi Aoyama、Toshio Takido、Mitsuo Kodomari
DOI:10.1055/s-2004-832812
日期:——
A simple and efficient method for the conversion of carbonyl compounds to oxathioacetals and dithioacetals by using polyphosphoric acid supported on silica gel (PPA/SiO2) as an acid catalyst have been developed. PPA/SiO2 is easily recovered from the reaction mixture and reused without a decrease in catalytic activity.
The chemistry of molecules containing sulfur attracts continuous attention as a consequence of the potential biological activity of this class of compounds (1). For example, tiapamil is an antianginal agent used in the treatment of angina pectoris (2). The protection of carbonyl functionality as a dithioacetal or a thioketal is an important tool in the multistep total synthesis of complex natural and