Exploring the limitations of the MacDonald '3 + 1' condensation in the preparation of porphyrins with fused electron-withdrawing heterocyclic rings: Synthesis of a bis(thiadiazolo)benzoporphyrin and a related benzocarbaporphyrin. Issue 48 (26th November 2020)

• Record Type: Journal Article
• Authors: Cillo, Catherine M.; Geiger, Mark A.; Lash, Timothy D.
• Is Part Of: Tetrahedron letters. Volume 61:Issue 48(2020)
• Publication Date: 2020-11-26
• Subjects: Porphyrin synthesis -- Extended chromophores -- Electron-deficient heterocycles -- Barton-Zard reaction -- Carbaporphyrins; Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1016/j.tetlet.2020.152576
• Languages: English
• ISSNs: 0040-4039

Abstract

Graphical abstract: Abstract: A pyrrole ethyl ester with a fused bis(thiadiazolo)benzo unit was prepared by reacting 4-nitrobenzo[1, 2- c :3, 4- c' ]bis(1, 2, 5)thiadiazole with ethyl isocyanoacetate in the presence of a non-nucleophilic base. Cleavage of the ester moiety, followed by reaction with a chloromethylpyrrole in refluxing pyridine, afforded a tripyrrane and subsequent acid-catalyzed condensation with pyrrole or indene dialdehydes gave porphyrinoids incorporating fused electron-deficient heterocyclic units.