Wavelength Control of Diastereodifferentiating Paterno-Buchi Reaction of Chiral Cyanobenzoates with Diphenylethene through Direct versus Charge-Transfer Excitation

摘要

The Paterno-Buechi reaction provides us with a versatile route to a variety of chiral oxetanes, which are often found in biologically important molecules, including taxol, preussin, and oxetanocin, and are recognized as promising drug-discovery modules. Thus, the manipulation of stereoselectivity by the use of allylic strain and hydrogen-bonding interactions has been a target of intensive study. Most Paterno-Buechi reactions are known to proceed through triplet 1,4-biradical intermediates, which either revert to the starting materials or cyclize to the corresponding oxetanes after spin inversion.