Manganese(III) acetate based oxidative cyclizations of 3-oxopropanenitriles with conjugated alkenes and synthesis of 4,5-dihydrofuran-3-carbonitriles containing heterocycles

4,5-Dihydrofuran-3-carbonitriles were obtained through oxidative cyclizations of 3-oxo-3-phenylpropanenitrile , 3-oxo-3-thien-2-ylpropanenitrile , 3-(2-furyl)-3-oxopropanenitirle , 3-(1-benzofuran-2-yl)-3-oxopropanenitrile , and 4,4-dimethyl-3-oxopropanenitrile mediated manganese(III) acetate with 1,1-diphenyl-1-butene and 1,2-diphenyl-1-pentene . The treatments of these 3-oxopropanenitriles with 2-thienyl substituted alkenes such as 2-[(E)-2-phenylvinyl]thiophene , 2-[(E)-1-methyl-2-phenylvinyl]thiophene , and 2-(1-phenylvinyl)thiophene formed 5-(2-thienyl)-4,5-dihydrofuran-3-carbonitriles in good yields (45–93%). As a result, 2-thienyl substituted alkenes formed products in higher yields than phenyl substituted derivatives.