Tandem oxidative isocyanide-based cycloaddition reactions in the presence of MIL-101(Cr) as a reusable solid catalyst

The tandem oxidative three-component synthesis of two types of the heterocycles such as furans and imidazopyridines, via isocyanides 1+4] cycloaddition reactions in the presence of MIL-101(Cr) under aerobic conditions are reported. When the 4-toluenesulfonylmethyl isocyanide was used, an unexpected 3+2] cycloaddition reaction of isocyanides with aldehydes accomplished and dihydrophenyloxazoles and phenyloxazoles produced. These syntheses were successfully carried out using a wide scope of the substrates.