title: Enhanced diastereoselectivity via confinement: photoisomerization of 2,3-diphenylcyclopropane-1-carboxylic acid derivatives within zeolites.
abstract: From the perspective of asymmetric induction, the photochemistry of 24 chiral esters and amides of cis-2,3-diphenylcyclopropane-1-carboxylic acid from excited singlet and triplet states has been investigated within zeolites. The chiral auxiliaries placed at a remote location from the isomerization site functioned far better within a zeolite than in solution. Generally, chiral auxiliaries with an aromatic or a carbonyl substituent performed better than the ones containing only alkyl substituents. A model based on cation-binding-dependent flexibility of the chiral auxiliary accounts for the observed variation in de between aryl (and carbonyl) and alkyl chiral auxiliaries within zeolites. Cation-dependent diastereomer switch was also observed in select examples.
authors.affiliation: Department of Chemistry, Tulane University, New Orleans, Louisiana 70118, USA.
authors.forename: J
authors.initials: J
authors.lastname: Sivaguru
authors.forename: Raghavan B
authors.initials: RB
authors.lastname: Sunoj
authors.forename: Takehiko
authors.initials: T
authors.lastname: Wada
authors.forename: Yumi
authors.initials: Y
authors.lastname: Origane
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Inoue
authors.forename: Vaidhyanathan
authors.initials: V
authors.lastname: Ramamurthy