Synthesis of substituted pyridyl ureas by selenium dioxide-catalyzed carbonylation

A series of commercially useful substituted pyridyl ureas have been synthesized via selenium dioxide-catalyzed reductive carbortylation of substituted nitrobenzene or substituted nitropyridine with amine as co-reagent and carbon monoxide as carbonyl reagent instead of phosgene in one-pot reaction. The recycling reusability of catalyst was also tested. It was also found that selenium dioxide-catalyzed reductive carbonylation of nitroaromatics exhibited reaction-controlled phase-transfer phenomena of the catalyst. (C) 2003 Elsevier B.V. All rights reserved.

Selective formation of aromatic amines by selenium-catalyzed reduction of aromatic nitro compounds with CO/H2O under atmospheric pressure

An efficient method for the catalytic reduction of aromatic nitro compounds to the corresponding aromatic amines is reported. In the presence of selenium as a catalyst, the aromatic nitro compounds are quantitively reduced by CO/H2O to form the corresponding amines under atmospheric pressure. The reduction occurs in high selectivity regardless of other reducible functionalities present on the aromatic ring. There exists a phase transfer process of the catalyst selenium in the reaction. (C) 2004 Elsevier B.V. All rights reserved.

Computational study on the addition of HCN to methanimine catalyzed by formamidine and formamide

In this paper, we have carried out a theoretical study on the addition of HCN to methanimine with formamidine or formamide using second-order Moller-Plesset perturbation (MP2) method with 6-31 + G(d,p) basis sets. At MP2 level. a high-energy, intermediate has been located for each pathway. The addition of HCN to methanimine with formamidine has the lowest free energy barrier according to the calculations at MP2 level. (C) 2004 Elsevier B.V. All rights reserved.

N-arylamides from selenium-catalyzed reactions of nitroaromatics and amides in the presence of carbon monoxide and mixed organic bases

N-Arylamides were exclusively obtained in moderate to good yields from selenium-catalyzed reactions of nitroaromatics with amides in the presence of CO and mixed organic bases Et3N and DBU.