Synthesis of glycoconjugated metalloporphyrins and their selective catalysis for alkane oxidation under mild conditions

Two glycoconjugated porphines, tetra[2-acetylglucosyl-oxo-phenyl]porphine [ T(o-glu)PPH2] and tetra[3-acetylglycosy-oxo-phenyl]porphine[T(m-glu)PPH2], were synthesized from the reaction of pyrrole with ortho-acetylglycosylate benzaldehyde and meta- acetylglycosylate benzaldehyde, respectively, by usi ng Lindsey' s method. Four glycoconjugated metalloporphyrins, chloro [tetra (o-2, 3,4, 6-O-acetylglucose-1-O-phenyl) porphinato] iron [T(o-glu)PPFeCl], chloro[tetra(o-2, 3, 4, 6-O-acetylglucose-1-O-phenyl) porphinato] manganes e, [T(o-glu) PPMnCl], chloro [tetra(m-2, 3, 4, 6-O-acetylglucose-1-O-phenyl ) porphinato] iron [T(m-glu) PPFeCl] and chloro[tetra(m-2, 3,4, 6-O-acetylg lucose-1-O-phenyl) porphinato] manganese [T(m-glu)PPMnCl] were prepared fro m these glycoconjugated porphines. The newly synthesized compounds were cha racterized by UV-vis spectroscopy, elemental analysis and H-1 NMR. The cata lytic oxidation of 2-methylbutane with PhIO as an oxidant at room temperatu re and under atmospheric pressure by four glycoconjugated metalloporphyrins was studied, The research showed that glycoconjugated metalloporphyrins ca talyzed regiospecifically the hydroxylation of the primary carbon-hydrogen bonds of 2-methylbutane, and that non-glycoconjugated metalloporphyrins cat alyzed selectively the oxidation of secondary and tertiary carbon-hydrogen bonds of 2-methylbutane. In contrast with metalloporphyrins without sugar g roups, the selective catalysis of these glycoconjugated metalloporphyrins f or hydrocarbon oxidation was closer to cytochrome P-450 monooxygenase.