Metallcarbonyl‐Synthesen, XXI. Einfache Synthese eines präparativ nützlichen Alkoxy(carbonyl)metallats

Abstract

Metal Carbonyl Syntheses, XXI. – Straightforward Synthesis of a Synthetically Useful Alkoxy(carbonyl)metallateAnionic methoxy complexes are formed upon carbonylation of ammonium perrhenate in methanol at 230–240°C. Thus, the dinuclear ionic complex [N(CH₃)₄][Re₂(CO)₆(μ‐OCH₃)₃] (2) results in 80% yield at CO pressures of ca. 100 bar, while the trinuclear derivative [N(CH₃)₄][Re₃(CO)₉(μ₃‐OCH₃)₃(μ₃‐OCH₃)] (3) is due to lower pressure conditions (ca. 50 bar); 2 yields the bis(carbene) complex 4 of formula fac‐Re(CO)₃L₂I upon treatment with a bis(imidazolium) iodide, thus demonstrating that carbonylrhenium chemistry not necessarily depends on the availability of Re₂(CO)₁₀.