One-pot synthesis of unsymmetrical benzils from aryl methyl ketones and arenes in the presence of selenous acid catalysed by p-toluenesulfonic acid monohydrate
A modified one-pot method for the synthesis of unsymmetrical and heteroaryl benzils from substituted acetophenones and unactivated or weakly activated arenes by the use of H2SeO3 and p-TsOH center dot H2O as catalysts at 35 degrees C is established. The present method is regioselective and avoids the use of p-TsOH center dot H2O in stoichiometric amount in the presence of H2SeO3 and afforded unsymmetrical benzils in good yields. (C) 2012 Elsevier Ltd. All rights reserved.
One-Pot Synthesis of Unsymmetrical Benzils by Oxidative Coupling Using Selenium Dioxide and p-Toluenesulfonic Acid Monohydrate
作者:Md. Rumum Rohman、Icydora Kharkongor、Mantu Rajbangshi、Hormi Mecadon、Badaker M. Laloo、Priti R. Sahu、Iadeishisha Kharbangar、Bekington Myrboh
DOI:10.1002/ejoc.201101012
日期:2012.1
The oxidative coupling of the α-carbon atom of aromatic ketones with unactivated arenes in the presence of seleniumdioxide and p-toluenesulfonic acid monohydrate is described. A number of unsymmetrical benzils have been prepared in good yields (38–75 %) with high regioselectivity. The generality and functional tolerance of this new protocol is demonstrated. The mechanistic pathway for the oxidative