A regioselective three component reaction of pyridine N-oxides, acyl chlorides and cyclic ethers

A novel 3-component reaction of pyridine N-oxides, acyl chlorides and cyclic ethers is described. Treatment of an electron defi-cient pyridine N-oxide with an acyl chloride in the presence of a cyclic ether at 25–50 °C leads to a substituted pyridine as a single regioisomer in up to 58% isolated yield. Isotopic labelling experiments and substrate scope support the reaction proceeding through a carbene intermediate