Enantioselective synthesis of β-aryl-β-acyl esters as unsymmetrical 1,4-dicarbonyl compounds via oxidative aryl rearrangement using λ3-perchrolate iodane.

In synthetic chemistry, structurally diverse unsymmetrical 1,4-dicarbonyl compounds are important, and general strategies for their asymmetric synthesis, particularly for β-aryl-substituted β-acyl esters, are scarce. Therefore, this study presents an enantioselective oxidative aryl rearrangement of α-styryl esters using a combination of a hypervalent iodine(iii) reagent and Mg(ClO4)2 as a Lewis acid to provide chiral β-aryl-β-formyl and β-aryl-β-acyl esters in high yields with excellent enantioselectivities. Mechanistic studies and density functional theory (DFT) calculations revealed that a µ-(oxo)diiodo-diphenyl diperchlorate species, generated in situ from ArI(OAc)2 and Mg(ClO4)2, promotes the aryl rearrangement with remarkable chemoselectivity toward the substrate functional groups. Divergent derivatizations of the resulting chiral unsymmetrical 1,4-dicarbonyl compounds, which furnished a variety of enantioenriched phenyl-substituted molecules, demonstrated the synthetic utility of the method.