Enantioselective Intramolecular [2 + 2]-Photocycloaddition Reactions of 4-Substituted Quinolones Catalyzed by a Chiral Sensitizer with a Hydrogen-Bonding Motif
作者:Christiane Müller、Andreas Bauer、Mark M. Maturi、M. Consuelo Cuquerella、Miguel A. Miranda、Thorsten Bach
DOI:10.1021/ja207480q
日期:2011.10.19
subjected to an intramolecular [2 + 2]-photocycloaddition. The reaction delivered the respective products in high yields (78-99%) and with good regioselectivity in favor of the straight isomer. If conducted in the presence of a chiral hydrogen-bonding template (2.5 equiv) at low temperature in toluene as the solvent, the reaction proceeded enantioselectively (83-94% ee). An organocatalytic reaction was achieved
A nanosized confined space with well-defined functional surfaces has great potential to control the efficiency and selectivity of catalytic reactions. Herein we report that a 1,6-diene, which normally forms an intramolecular [2+2] cycloadduct under photoirradiation, preferentially undergoes a photoinduced olefin migration in a porous crystal, metal-macrocycle framework (MMF), and alternatively [2+2]