[2 + 2] cycloaddition of alkynes with alkenes would normally require UV light irradiation. Here, the authors report an alkyne–alkene [2 + 2] cycloaddition based on visible light energy transfer photocatalysis, both inter- and intramolecularly, to afford cyclobutenes and 1,3-dienes.
- Sujin Ha
- Yeji Lee
- Cheol-Min Park