Direct oxidative C(sp3)─H/C(sp2)─H coupling reaction using recyclable Sr-doped LaCoO3 perovskite catalyst

A strontium-doped lanthanum cobaltite perovskite, La_0.6Sr_0.4CoO₃, was prepared and utilized as a recyclable heterogeneous catalyst for the direct oxidative C(sp³)─H/C(sp²)─H coupling reaction between cyclic ethers and alkenes or coumarins to achieve corresponding α-functionalized ethers. The α-functionalization of cyclic thioethers or amides with alkenes or coumarins was also achieved via this protocol. The La_0.6Sr_0.4CoO₃ catalyst exhibited better performance than a variety of homogeneous and heterogeneous catalysts. Utilizing a recyclable catalyst would offer a greener option for the direct oxidative C(sp³)─H/C(sp²)─H coupling reaction. To our best knowledge, the C(sp³)─H/C(sp²)─H coupling between olefins and ethers to generate α-functionalized ethers using a heterogeneous catalyst has not been previously reported, and the α-functionalization of cyclic thioethers or amides with alkenes or coumarins is new.