Unusual [2+4] and [2+2] Cycloadditions of Arenes in the Confined Cavity of Self-Assembled Cages

Unusual [2+4] and [2+2] cross-cycloadditions of arenes were efficiently promoted within a self-assembled coordination cage. For example, triphenylene underwent the Diels−Alder reaction with N-cyclohexylmaleimide in good yield in the confined cavity of the cage, despite its inertness under ordinary conditions. Syn-stereoselective photodimerization of pyrene and N-cyclohexylmaleimide was also carried out quantitatively within the cage. The structures of these cross adducts were confirmed by NMR and X-ray crystallographic analysis.芳烃在自组装配位笼内可高效发生非常规的[2+4]与[2+2]交叉环加成反应。例如，尽管三亚苯在常规条件下呈惰性，但在该笼的受限空腔中，其可与N-环己基马来酰亚胺发生狄尔斯-阿尔德（Diels-Alder）反应，且收率良好。此外，芘与N-环己基马来酰亚胺的顺式立体选择性光二聚反应也可在该笼内定量完成。上述交叉环加成产物的结构均通过核磁共振（NMR）与X射线晶体学分析得以确认。