Isonitriles as supporting and non-innocent ligands in metal catalysis

Abstract

Isonitriles are unique ligands for metal catalysis, owing to the possibility of their steric and electronic tuning as well as their non-innocent nature to undergo transformations with nucleophiles.

Eightfold Electrophilic Methylation of Octacyanotungstate [W(CN)8]4–/3–: Preparation of Homoleptic, Eight-Coordinate Methyl Isocyanide Complexes [W(CNMe)8]4+/5+

“…8 If compared with homoleptic carbonyl complexes where ̃(CO) differ by hundreds of wavenumbers in dependence on the oxidation state of the metal, 34 this effect seems to be less pronounced for homoleptic alkyl isocyanide complexes due to their weaker π -acceptor properties. 35…”

Synthesis and Characterization of Bidentate Isonitrile Iron Complexes

“…[3], [4] Isonitriles can be electronically and sterically tuned through modification of their organic substituents, which makes them versatile ligands for metal catalysis. [5] Chelating bis-(isonitriles) confer rigidity to metal complexes, which has been proven to be especially valuable for the design of 3dmetal complexes with sufficient excited-state lifetimes to efficiently initiate single electron transfer (SET) processes. This approach has been successful for copper [6] , molybdenum [7] , and rhenium [8] , providing alternatives to established but scarce ruthenium-and iridium-based photocatalysts.…”

Synthesis and Characterization of Bidentate Isonitrile Iron Complexes

“…[3], [4] Isonitriles can be electronically and sterically tuned through modification of their organic substituents, which makes them versatile ligands for metal catalysis. [5] Chelating bis-(isonitriles) confer rigidity to metal complexes, which has been proven to be especially valuable for the design of 3dmetal complexes with sufficient excited-state lifetimes to efficiently initiate single electron transfer (SET) processes. This approach has been successful for copper [6] , molybdenum [7] , and rhenium [8] , providing alternatives to established but scarce ruthenium-and iridium-based photocatalysts.…”

“…In comparison to monodentate isonitrile ligands, the reactivity and coordination chemistry of bidentate isonitriles is generally unexplored. [5] Given the linear structure of the isonitrile unit, such ligands need to form much larger chelates relative to the typical N,N-or P,P-ligands that are commonly found in 5-and 6-membered rings. The minimal ring size in a bidentate isonitrile-metal complex was found to be 12 [17] .…”

“…Following this design concept, a number of iron(II) complexes with bidentate isonitrile ligands was realized, representative examples are D-G (Figure 1). [5], [18]- [21] Our research group has previously been interested in the synthesis and reactivity of low-oxidation polyarene and alkene ferrates. [22] Such complexes have been used for various applications, including the activation of small molecules (e.g.…”