2,4,4,6-Tetrabromo-2,5-cyclohexadienone (TABCO), N-Bromosuccinimide (NBS) and Bromine as Efficient Catalysts for Dithioacetalization and Oxathioacetalization of Carbonyl Compounds and Transdithioacetalization Reactions
作者:Nasser Iranpoor、Habib Firouzabadi、Hamid Reza Shaterian、M. A. Zolfigol
DOI:10.1080/10426500211712
日期:2002.5.1
6-tetrabromo-2,5-cyclohexadienone (TABCO), N-bromosuccinimide (NBS), and bromine as efficient catalysts for conversion of carbonyl compounds to their cyclic and acyclic dithioacetals and 1,3-oxathiolanes under mild reaction conditions are described. These catalysts are also used for efficient transdithioacetalization of acetals, diacetals, ketals, acylals, enamines, hydrazones, and oximes with high
Direct anodic (thio)acetalization of aldehydes with alcohols (thiols) under neutral conditions, and computational insight into the electrochemical formation of the acetals
A versatile protocol for the production of acetals/thioacetals by means of direct electrochemical oxidation is developed here under neutral conditions, providing (thio)acetals with good functional group tolerance and a wide scope for both aldehydes and (thio)alcohols. DFT calculations reveal that direct electron transfer from the anode plays a key role in carbonyl activation during this acid free acetalization
A modified procedure for the preparation of a silica chloride with higher chloride capacity than that reported is described. Moreover, this silica chloride was found to be an effective catalyst for chemoselective and highly efficient transdithioacetalization of different classes of acetals.
A Simple and Convenient Catalytic Procedure for the Preparation of Dithioacetals
作者:Andrew E. Graham
DOI:10.1080/00397919908085819
日期:1999.2
Abstract A simpleprocedure for the synthesis of cyclic and acyclic thioacetals from aldehydes is described which employs hydrogen chloride solutions generated from acetyl chloride and methanol. It was observed that the reaction could be carried out using catalytic quantities of acetyl chloride, potentially allowing acid sensitive substrates to be used under these conditions.
Heteropoly Acids as Heterogeneous Catalysts for Thioacetalization and Transthioacetalization Reactions
作者:Habib Firouzabadi、Nasser Iranpoor、Kamal Amani
DOI:10.1055/s-2002-19300
日期:——
Heteropoly acids are effective solid catalysts for the thioacetalization of carbonyl compounds. Tungstophosphoric acid (H 3 PW 1 2 O 4 0 ), 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