Nucleophiles Target the Tungsten Center Over Acetylene in Biomimetic Models.

ABSTRACT: Inspired by the first shell mechanism proposed for the tungstoenzyme acetylene hydratase, the electrophilic reactivity of tungsten-acetylene complexes [W(CO)(C₂H₂)(6-MePyS)₂] (1) and [WO(C₂H₂)(6-MePyS)₂] (2) was investigated. The biological nucleophile water/hydroxide and tert-butyl isocyanide were employed. Our findings consistently show that, regardless of the nucleophile used, both tungsten centers W(II) and W(IV), respectively, are the preferred targets over the coordinated acetylene. Treatment of 2 with aqueous NaOH led to protonation of coordinated acetylene to ethylene, pointing toward the Brønsted basic character of the coordinated alkyne instead of the anticipated electrophilic behavior.

SUBMITTER: Corovic MZ 

PROVIDER: S-EPMC11220757 | biostudies-literature | 2024 Jul

REPOSITORIES: biostudies-literature