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Axially chiral molecules have been widely used in inorganic, material and medicinal chemistry. Compared with well-established N-heterocyclic carbene (NHC)-catalyzed asymmetric construction of centrally chiral molecules, NHC-catalyzed atroposelective synthesis of axially chiral molecules remains largely underdeveloped. Notably, alkynyl acyl azolium intermediates were commonly used in constructing a heteroaryl ring to furnish axially enantioenriched heteroaryl-aryls. The inherent character of the intermediates often led to react with sterically hindered substrates difficultly. Herein, we have successfully disclosed the atroposelective synthesis of axially chiral heteroaryl-aryls from sterically hindered enols through the use of chiral NHCs as catalysts for highly enantioselective Coates-Claisen rearrangements
via
catalytically generated α,β-unsaturated acyl azoliums. This approach will enable the concise synthesis of valuable tetra-
ortho
-substituted 2-pyrones in one step with good yield and chirality control.