Solid-phase synthesis of asymmetrically substituted "AB3-type" phthalocyanines.
Synthesis of phthalocyanines with asymmetrical substitution on the periphery is often difficult due the problems in purification of the phthalocyanine mixtures obtained. Using a poly(ethylene glycol) (PEG)-based support with a Wang-type linker, we have developed the synthesis of monohydroxylated, oligoethylene glycol substituted phthalocyanines utilizing an amidine-base-promoted phthalonitrile tetramerization reaction. The use of a hydrophilic support allows symmetrical phthalocyanine product formed in solution to be readily and completely removed by washing while leaving the "AB3" product on the support. Acid cleavage with 10% trifluoroacetic acid provides the pure unsymmetrically substituted Pc. This method was applied to several metallo Pcs. Additionally, methods to avoid premature reactions on-resin that give A2B2 products are provided.
Erdem
S Sibel
SS
Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, USA.
Nesterova
Irina V
IV
Soper
Steven A
SA
Hammer
Robert P
RP
D004396:Coloring Agents / Q000138:chemical synthesis; D007211:Indoles / Q000138:chemical synthesis*; D015394:Molecular Structure
D004396:Coloring Agents; D007211:Indoles