Iron(II) Chloride Catalyzed Alkylation of Propargyl Ethers: Direct Functionalization of an sp³ C-H Bond Adjacent to Oxygen

Abstract

Iron(II) chloride catalyzed direct alkylation of sp³ C-H bond adjacent to oxygen in propargyl ethers has been accomplished by the use of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) as oxidant under mild reaction conditions. The reaction proceeded smoothly with a variety of 1,3-diketones leading to β-dicarbonyl ether in moderate yields. In the absence of 1,3-diketones, ynenones were produced by the use of iron(III) chloride and DDQ.