p-TsOH catalysed KSF solid supported Michael addition with substituted isoxazoles and their reductive cyclisation to isoxazolo[4,5-b]azepines

Abstract

The Michael addition of substituted isoxazoles to substituted chalcones and 1,3-dicarbonyl compounds in presence of p-toluenesulfonic acid catalyst supported on KSF-clay proceed very efficiently and furnished the Michael adducts in excellent yields. The Michael adducts underwent reductive cyclization on treatment with SnCl 2 -MeOH to afford substituted isoxazolo [4,5-b]azepines in high yields.