Light-induced [2 + 2] cycloaddition is the most efficient way to generate cyclobutanes, while suffering from limitations of specific selectivity. Here the authors report a cage-confined photocatalytic [2 + 2] cycloaddition to enable the unusual production of syn-head-to-head cyclobutane derivatives selectively.
- Jing-Si Wang
- Kai Wu
- Cheng-Yong Su
