A novel modular approach to triazole-functionalized phthalocyanines using click chemistry.
A novel, elegant, and significantly improved protocol for the synthesis of a protected octaacetylene phthalocyanine is described. Inexpensive, mild, and environmentally benign iodination of 1,2-dibromobenzene and subsequent optimized chemoselective palladium-catalyzed cyanation are employed to effectively build up the key intermediate 4,5-dibromophthalonitrile in two steps. Introduction of the tert-butyldimethylsilyl-protected acetylene moieties via a Sonogashira cross-coupling provides the desired phthalonitrile precursor that, after cyclization, yielded the protected octaacetylene phthalocyanine. Subsequently, in situ deprotection and "clicking" are employed as a highly efficient and quantitative route to a novel class of octatriazole-functionalized phthalocyanines. The ability of such triazole-derived phthalocyanines to form well-defined supramolecular structures upon doping with zinc(II) triflate is demonstrated.
Jurícek
Michal
M
Institute for Molecules and Materials, Radboud University Nijmegen, Toernooiveld 1, 6525 ED Nijmegen, The Netherlands.
Kouwer
Paul H J
PH
Rehák
Juraj
J
Sly
Joseph
J
Rowan
Alan E
AE
D000480:Alkynes / Q000138:chemical synthesis* / Q000737:chemistry; D002384:Catalysis; D003500:Cyclization; D007211:Indoles / Q000138:chemical synthesis* / Q000737:chemistry; D054833:Isoindoles; D015394:Molecular Structure; D010165:Palladium / Q000737:chemistry; D014230:Triazoles / Q000737:chemistry*
D000480:Alkynes; D007211:Indoles; D054833:Isoindoles; D014230:Triazoles; D010165:Palladium; C013647:phthalocyanine