Phosphine-catalyzed [3+2] cycloaddition reaction of methyl 2,3-butadienoate and N-tosylimines. A novel approach to nitrogen heterocycles

Article abstract of DOI:10.1016/S0040-4039(97)00656-4

In the presence of a catalytic amount of triphenylphosphine, methyl 2,3-butadienoate smoothly reacted with aromatic or heteroaromatic N-tosylimines at room temperature to afford the [3+2] cycloaddition product in excellent yield.