Electrochimica Acta, Vol.53, No.15, 5033-5038, 2008
Electrocatalytic tandem Knoevenagel-Michael reaction of 3-methyl-2-pyrazolin-5-ones, aryl aldehydes and cyano-functionalized C-H acids: Facile and convenient multicomponent way to substituted 3-(5-hydroxy-3-methylpyrazol-4-yl)-3-arylpropionitriles
Electrochemically induced catalytic tandem Knoevenagel-Michael reaction of 3-methyl-2-pyrazolin-5-ones, aryl aldehydes and malononitrile or alkyl cyanoacetates in alcohols in an undivided cell in the presence of sodium bromide as an electrolyte results in the formation of substituted 3-(5-hydroxy-3-methylpyrazol-4-yl)-3-arylpropionitriles in 75-97% yields. The developed efficient electrocatalytic approach to the corresponding 3-(5-hydroxy-3-methylpyrazol-4-yl)-3-arylpropionitriles is beneficial from the viewpoint of diversity-oriented large-scale processes and represents novel, facile and environmentally benign synthetic concept for multicomponent reactions strategy. (C) 2008 Elsevier Ltd. All rights reserved.