Iron-catalyzed alkenylation of cyclic ethers via decarboxylative sp3(C)–sp2(C) coupling

An efficient Fe(acac)3-catalyzed decarboxylative C(sp2)–C(sp3) coupling reaction via oxidation of C–H bond adjacent to an oxygen atom has been developed successfully, in which cyclic ethers are selectively transformed into the corresponding alkenylation products with good chemical yields and excellent stereoselectivities. The mechanism was studied and the reaction was supposed to proceed through a radical oxidative coupling process.