Asymmetric Iodonio-[3,3]-Sigmatropic Rearrangement to Access Chiral α‑Aryl Carbonyl Compounds

Here we describe
an asymmetric [3,3]-sigmatropic rearrangement
of aryl iodanes that enables the enantioselective α-arylation
of chiral 2-oxazolines, thereby producing valuable chiral α-aryl
carbonyl compounds. The success of this protocol hinges on the selective
assembly of aryl iodanes with 2-oxazolines and the smooth deprotonation
of the in situ-generated iodonium–imine species. The nearly
neutral and mild conditions of the reaction allow it to tolerate a
wide variety of functional groups. Moreover, the remaining iodine
atom in the products not only provides a versatile platform for further
elaboration of such molecules but also supplies the asymmetric hypervalent
iodine chemistry with a new class of chiral scaffolds.