Light-Induced Transfer of Molecular Chirality in Solution: Enantiospecific Photocyclization of Molecularly Chiral Acrylanilides

Molecularly chiral o-tert-butylacrylanilides undergo enantiospecific 6pi-photocyclization to yield 3,4-dihydroquinolin-2-ones with very high enantioselectivity (>90%) in solution. The photocyclization results in the removal of the ortho tert-butyl substituent, presumably via a zwitterionic intermediate. Beta-substitution in the alkene is found to be critical for the transfer of molecular chirality (axial chirality) in the reactant to point chirality in the photoproduct(s).