title: Synthesis and reactivity of mononuclear iron models of [Fe]-hydrogenase that contain an acylmethylpyridinol ligand.
abstract: [Fe]-hydrogenase has a single iron-containing active site that features an acylmethylpyridinol ligand. This unique ligand environment had yet to be reproduced in synthetic models; however the synthesis and reactivity of a new class of small molecule mimics of [Fe]-hydrogenase in which a mono-iron center is ligated by an acylmethylpyridinol ligand has now been achieved. Key to the preparation of these model compounds is the successful C-O cleavage of an alkyl ether moiety to form the desired pyridinol ligand. Reaction of solvated complex [(2-CH2CO-6-HOC5H3N)Fe(CO)2(CH3CN)2](+)(BF4)(-) with thiols or thiophenols in the presence of NEt3 yielded 5-coordinate iron thiolate complexes. Further derivation produced complexes [(2-CH2CO-6-HOC5H3N)Fe(CO)2(SCH2CH2OH)] and [(2-CH2CO-6-HOC5H3N)Fe(CO)2(CH3COO)], which can be regarded as models of FeGP cofactors of [Fe]-hydrogenase extracted by 2-mercaptoethanol and acetic acid, respectively. When the derivative complexes were treated with HBF4 ⋅Et2O, the solvated complex was regenerated by protonation of the thiolate ligands. The reactivity of several models with CO, isocyanide, cyanide, and H2 was also investigated.
authors.affiliation: School of Chemical Engineering and Technology, Harbin Institute of Technology, Harbin 150001 (China).
authors.forename: Bowen
authors.initials: B
authors.lastname: Hu
authors.forename: Dafa
authors.initials: D
authors.lastname: Chen
authors.forename: Xile
authors.initials: X
authors.lastname: Hu
mesh_terms: D000215:Acylation; D006864:Hydrogenase / Q000737:chemistry*; D007506:Iron-Sulfur Proteins / Q000737:chemistry*; D008024:Ligands; D008745:Methylation; D008958:Models, Molecular; D011725:Pyridines / Q000737:chemistry*; D013438:Sulfhydryl Compounds / Q000737:chemistry*
chemical_list: D007506:Iron-Sulfur Proteins; D008024:Ligands; D011725:Pyridines; D013438:Sulfhydryl Compounds; C118830:iron hydrogenase; D006864:Hydrogenase
keywords: carbonyl complexes; enzyme models; hydrogenases; iron; thiolates