Asymmetric induction in an intramolecular [2+2] photocycloaddition within chirally modified zeolite supercages

Photoirradiation of 1-cyano-2-(5-methyl-2-oxa-4-hexenyl)naphthalene, included in NaY zeolites along with chiral inductors, such as diethyl tartrate or phenylalaninol, gives an intramolecular [2+2] photocycloadduct with a maximum 15% ee. The degree of enantioselectivity was found to depend on the Si/Al ratio, the nature of the cations in the zeolites, the structure of the chiral inductors, and the molar ratio of substrate and chiral inductors.

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