31-Arylation of a chlorophyll-a derivative through Friedel–Crafts alkylation. (24th September 2022)

• Record Type: Journal Article
• Authors: Sakaguchi, Kana; Tamiaki, Hitoshi
• Is Part Of: Tetrahedron. Volume 123(2022)
• Publication Date: 2022-09-24
• Subjects: Acidic dehydration -- Fluorescence emission -- Homoconjugation -- Intermolecular reaction -- Substitution effect -- Visible absorption; Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1016/j.tet.2022.132981
• Languages: English
• ISSNs: 0040-4020

Abstract

Abstract: Methyl 3-hydroxymethyl-pyropheophorbide- a, one of the chlorophyll- a derivatives, was reacted with methylated and/or methoxylated benzenes as well as unsubstituted benzene in the presence of p -toluenesulfonic acid to give the corresponding 3-arylmethyl-chlorins. The Friedel–Crafts alkylation products exhibited almost the same ultraviolet–visible absorption and fluorescence emission spectra in a diluted dichloromethane solution. The substituents on the 3 1 -phenyl group in the intermolecularly dehydrated products slightly affected the absorption and emission data due to no direct π-conjugation of the 3 1 -aryl group with the chlorin moiety through the 3-methylene linker. The synthetic aryl-chlorin conjugates efficiently absorb purple and red light and highly fluoresce at a red to far-red region. Graphical abstract: Image 1