5849-03-6Relevant articles and documents
Mild Deprotection of Dithioacetals by TMSCl/NaI Association in CH3CN
Yao, Yunxin,Zhao, Guangkuan,Hamze, Abdallah,Alami, Mouad,Provot, Olivier
, p. 5775 - 5779 (2020/08/17)
A mild process using a combination of TMSCl and NaI in acetonitrile is used to regenerate carbonyl compounds from a variety of dithiane and dithiolane derivatives. This easy to handle and inexpensive protocol is also efficient to deprotect oxygenated and mixed acetals as 1,3-dioxanes, 1,3-dioxolanes and 1,3-oxathianes quantitatively. As a possible extension of this method, it was also shown that nitrogenated substrates such as hydrazones, N-tosylhydrazones, and ketimines reacted well under these conditions to give the expected ketones in high yields. The methodology proposed herein is a good alternative to the existing methods since it does not use metals, oxidants, reducing agents, acidic or basic media, and keto-products were obtained in high to excellent yields.
Chemoselective dithioacetalization and oxathioacetalization of carbonyl compounds using alumina sulfuric acid as catalyst
Shaterian, Hamid Reza,Hosseinian, Asghar,Ghashang, Majid
experimental part, p. 4097 - 4106 (2009/04/11)
Carbonyl compounds have been successfully converted into their corresponding dithiolane, dithiane, and oxathiolane derivatives using a catalytic amount of alumina sulfuric acid (Al2O3-SO3H) with excellent yields at room temperature in short reaction times under mild conditions. This simple method is a highly chemoselective procedure for protection of aldehydes in the presence of ketones, and the heterogeneous catalyst can be recovered and reused several times without any loss of its activity. Copyright Taylor & Francis Group, LLC.
Heteropoly acids as heterogeneous catalysts for thioacetalization and transthioacetalization reactions
Firouzabadi,Iranpoor,Amani
, p. 59 - 62 (2007/10/03)
Heteropoly acids are effective solid catalysts for the thioacetalization of carbonyl compounds. Tungstophosphoric acid (H3PW12O40), was found to be an effective and a highly selective catalyst for the thioacetalization of aldehydes, ketones and for the transthioacetalization of acetals, acylals and O,S-acetals which proceeded in excellent yields in the absence of solvent. The catalyst has also been successfully applied to the chemoselective conversion of α- or β-diketones and a β-keto ester into the corresponding dithioacetals. Sterically hindered carbonyl compounds such as camphor and benzophenone were also converted to their corresponding thioacetals in refluxing petroleum ether in 89-94percent yields. Surprisingly, anthrone was reduced to anthracene in 91percent yield.
