Expeditious Synthesis of Glycosylated Phthalocyanines

Abstract

3,4-Dicyanophenyl O- and S-glycosides in the gluco, galacto, lacto, and cellobiose series were prepared in virtually quantitative yield through nucleophilic aromatic substitution of 4-nitrophthalonitrile with acetyl-protected glycoses and 1-thio-glycoses. Similarly, 2-(3,4-dicyanophenoxy)ethyl 2,3,4,6-tetra-O-acetyl-β-d-gluco- and galacto-pyranosides were obtained by nucleophilic substitution of 2-(tosyloxy)ethyl 2,3,4,6-tetra-O-acetyl-β-d-gluco- and -galactopyranoside with 3,4-dicyanophenol in 82% and 94% yields, respectively. All glycosides were deacetylated and tetramerized to the corresponding glycosylated zinc(II) phthalocyanines without further purification using a template condensation in 42-54% yields.