The synthesis of benzocyclobutenes is reported through Pd(II)-catalysed γ,δ-methylene C(sp3)–H bond activation and [2 + 2] annulation between aliphatic carboxylic acids and dihaloarenes, using bidentate carboxyl-pyridone ligands. Regiocontrol is achieved in benzocyclobutene formation through the differentiation of reactivity between the aryl iodide and bromide sites.
- Liang Hu
- Jie-Lun Yan
- Jin-Quan Yu