title: Oxidations of chromene-annulated chlorins.
abstract: A chromene-annulated chlorin is a meso-pentafluorophenyl-2,3-dihydroxychlorin in which one of the hydroxy groups is linked to the ortho-position of a flanking meso-aryl group, thereby forming an annulated chromene moiety; the second hydroxy group is unprotected. This report illustrates the oxidation chemistry of the chromene-annulated chlorin under a number of different oxidation conditions. In some reactions, chromene annulation is retained and the non-protected alcohol is oxidized, generating chlorin-like chromophores carrying pyrroline β-carbons in oxidation states between those found in typical porphyrins and chlorins. Other products have lost the chromene moiety. The reactivity of the pyrroline carbon with respect to undergoing radical chemistry is shown with the formation of a number of products following a Swern oxidation, including the formation of two directly linked pyrroline-pyrroline and pyrroline-pyrrole chlorin dimers. This work contributes to the further understanding of the chemistry of chlorins. Selected compounds possess functionalities at their periphery susceptible to nucleophilic attack by MeOH, suggesting their use as chemosensors.
authors.affiliation: Department of Chemistry, University of Connecticut, Storrs, CT 06269-3060, USA. c.bruckner@uconn.edu.
authors.forename: Nisansala
authors.initials: N
authors.lastname: Hewage
authors.affiliation: Department of Chemistry, Youngstown State University, One University Plaza, Youngstown, OH 44555-3663, USA.
authors.forename: Matthias
authors.initials: M
authors.lastname: Zeller
authors.affiliation: Department of Chemistry, University of Connecticut, Storrs, CT 06269-3060, USA. c.bruckner@uconn.edu.
authors.forename: Christian
authors.identifier: http://orcid.org/0000-0002-1560-7345
authors.initials: C
authors.lastname: Brückner