Iron Coordination Chemistry of Phenylpyruvate: An Unexpected kappa3-bridging mode that leads to oxidative cleavage of the C2-C3 bond.
One mononuclear iron(II)-phenylpyruvate complex [Tp(Ph2)Fe(II)(PPH)] (1) of the tridentate face-capping Tp(Ph2) ligand and two dinuclear iron(II)-phenylpyruvate enolate complexes [(6-Me3-TPA)2Fe(II)2(PP)]2+ (2) and [(6-Me3-TPA)2Fe(II)2(2-NO2-PP)]2+ (3) of the tetradentate 6-Me3-TPA ligand are reported to demonstrate two different binding modes of phenylpyruvate to the iron(II) centers. Phenylpyruvate binds in a kappa2-(O,O) manner to the mononuclear Fe(II)(Tp(Ph2)) center of 1 but bridges in a kappa3-(O,O,O) fashion to the two Fe(II)(6-Me3-TPA) centers of 2 and 3. Mononuclear complex 1 reacts with O2 to undergo oxidative decarboxylation and ortho-hydroxylation of one of the aromatic rings of the Tp(Ph2) ligand. In contrast, dinuclear complexes 2 and 3 react with O2 to undergo oxidative cleavage of the C2-C3 bond of phenylpyruvate.
Paine
Tapan K
TK
Department of Chemistry and Center for Metals in Biocatalysis, University of Minnesota, 207 Pleasant St. S.E., Minneapolis, Minnesota 55455, USA.
Zheng
Hui
H
Que
Lawrence
L
D040761:Biomimetic Materials / Q000737:chemistry; D018360:Crystallography, X-Ray; D005296:Ferrous Compounds / Q000737:chemistry* / Q000302:isolation & purification; D007700:Kinetics; D006899:Mixed Function Oxygenases / Q000737:chemistry / Q000378:metabolism; D008958:Models, Molecular; D008968:Molecular Conformation; D015394:Molecular Structure; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry*; D010667:Phenylpyruvic Acids / Q000737:chemistry*
D005296:Ferrous Compounds; D010667:Phenylpyruvic Acids; D006899:Mixed Function Oxygenases; D010100:Oxygen