A Biomimetic Model for the Active Site of [Fe]‑H2ase Featuring a 2‑Methoxy-3,5-dimethyl-4-phosphato-6-acylmethylpyridine Ligand
journal contributionposted on 2019-10-28, 17:34 authored by Li-Cheng Song, Liang Zhu, Bei-Bei Liu
Herein, we report the first 3,5-dimethyl-4-phosphatopyridine moiety containing [Fe]-H2ase model, [2-MeO-3,5-Me2-4-OPO(OPh)2-6-COCH2C5N]Fe(CO)2(η2-6-Me-2-SC5H3N) (7), prepared by a multistep synthetic method including seven separate reaction steps. The first three reaction steps are utilized to prepare the organic precursors 4-TBSO-3,5,6-trimethyl-2-pyridone (1), 2-methoxy-4-TBSO-3,5,6-trimethylpyridine (2), and 2-methoxy-4-TBSO-3,5-dimethyl-6-chloromethylpyridine (3). The next three reaction steps are used to prepare the organometallic precursors (2-MeO-4-TBSO-3,5-Me2-6-COCH2C5N)Fe(CO)3I (4), (2-MeO-4-TBSO-3,5-Me2-6-COCH2C5N)Fe(CO)2(η2-6-Me-2-SC5H3N) (5), and (2-MeO-4-HO-3,5-Me2-6-COCH2C5N)Fe(CO)2(η2-6-Me-2-SC5H3N) (6). The final step is employed to prepare target model 7 by an esterification reaction of 6 with OP(OPh)2Cl in the presence of Et3N. All of the prepared organic and organometallic compounds are new and have been characterized by elemental analysis and spectroscopy and, for some of them, by X-ray crystallography.