Synthesis of Enantioenriched N-Aryl-2-pyridones with Chiral C-N Axes by Rhodium-Catalyzed [2+2+2] Cycloaddition of Alkynes with Isocyanates

Enantioenriched N-aryl-2-pyridones with axially chiral C-N bonds were prepared by a cationic rhodium(I)-BINAP or tol-BINAP-catalyzed enantioselective [2+2+2] cycloaddition of alkynes with ortho-substituted phenyl isocyanates.