In Situ Generated HypoIodite Activator for the C2 Sulfonylation of Heteroaromatic N-oxides

A mild approach for direct C2 sulfonylation of heteroaromatic N-oxides with sulfonyl hydrazides affording 2-sulfonyl quinolines/pyridines has been developed. A variety of heteroaromatic N-oxides and sulfonyl hydrazides participate effectively in this transformation which uses hypoiodites (generated in situ from NaI and TBHP) as a means of substrate activators. In this reaction, the N-oxide plays a dual role, acting as a traceless directing group as well as a source of oxygen atom.