Synthesis of Phthalocyanines with a Pentafluorosulfanyl Substituent at Peripheral Positions.
The pentafluorosulfanyl (SF5) group is more electronegative, lipophilic and sterically bulky relative to the well-explored trifluoromethyl (CF3) group. As such, the SF5 group could offer access to pharmaceuticals, agrochemicals and optoelectronic materials with novel properties. Here, the first synthesis of phthalocyanines (Pcs), a class of compounds used as dyes and with potential as photodynamic therapeutics, with a SF5 group directly attached on their peripheral positions is disclosed. The key for this work is the preparation of a series of SF5-containing phthalonitriles, which was beautifully regio-controlled by a stepwise cyanation via ortho-lithiation/iodination from commercially available pentafluorosulfanyl arenes. The macrocyclization of the SF5-containing phthalonitriles to SF5-substituted Pcs required harsh conditions with the exception of the synthesis of β-SF5-substituted Pc. The regiospecificity of the newly developed SF5-substituted Pcs observed by UV/Vis spectra and fluorescence quantum yields depend on the peripheral positon of the SF5 group.
Department of Frontier Materials Nagoya Institute of Technology Gokiso, Showa-ku Nagoya 466-8555 Japan.
Norihito
N
Iida
Department of Frontier Materials Nagoya Institute of Technology Gokiso, Showa-ku Nagoya 466-8555 Japan.
Kenta
K
Tanaka
Department of Nanopharmaceutical Sciences Nagoya Institute of Technology Gokiso, Showa-ku Nagoya 466-8555 Japan.
Etsuko
E
Tokunaga
Department of Nanopharmaceutical Sciences Nagoya Institute of Technology Gokiso, Showa-ku Nagoya 466-8555 Japan.
Satoru
S
Mori
Pharmaceutical Division Ube Industries, Ltd. Seavans North Bldg., 1-2-1 Shibaura, Minato-ku Tokyo 105-8449 Japan.
Norimichi
N
Saito
Department of Frontier Materials Nagoya Institute of Technology Gokiso, Showa-ku Nagoya 466-8555 Japan; Department of Nanopharmaceutical Sciences Nagoya Institute of Technology Gokiso, Showa-ku Nagoya 466-8555 Japan.
Norio
N
Shibata
macrocycles; organic synthesis; pentafluorosulfanyl group; phthalocyanines; ultraviolet/visible spectroscopy