Supramolecular systems as microreactors: control of product selectivity in organic phototransformation

This Account reviews the developments in microreactor-controlled selectivity in organic phototransformation. Photocycloaddition of alpha,omega-diaryl compounds with long flexible chains within Y-type zeolite and low-density polyethylene films leads to formation of intramolecular cyclomers to the exclusion of intermolecular products. ZSM-5 zeolite, Nafion membranes, and vesicles as hosts direct photosensitized oxidation of alkenes selectively toward either the energy-transfer-mediated or the electron-transfer-mediated products. Zeolites, Nafion membranes, and microemulsions as microreactors remarkably control chemo-, regio-, and stereoselectivity in the photochemical reaction of phenyl phenylacetates, photocycloaddition of anthracenes, and photocyclization of azobenzene and stilbazole.