Synthesis and Reactivity of Cp*Ir^III Complexes with a C–S Chelate Displaying Metal/Sulfur Bifunctionality

Abstract

A half-sandwich thiolatoiridium complex bearing a five-membered C−S chelating ligand has been synthesized via cyclometalation of triphenylmethyl mercaptan. The thiametallacycle crystallizes as a coordinatively saturated dimer, bridged with the thiolato ligand. Two-electron donors, such as phosphines and CO, readily coordinate to the thiametallacycle having a bimetallic core to afford the corresponding mononuclear C−S chelating thiolato complexes. The thiolato moiety is alkylated with electrophilic organic halides, including methyl iodide, benzyl bromide, and allyl halides, to yield the corresponding mononuclear thioether complexes in a stereoselective manner that validates the nucleophilic character of the coordinating sulfur atom on the thiairidacycle. By treatment of the dinuclear complex with alkynes, the carbon−carbon triple bonds insert into the thiolato−metal bond selectively to give the corresponding tridentate thioether complexes having a metal−sulfur bond. The insertion of unsymmetrical acetylenecarboxylates provides regioselective adducts where the ester substituent attaches to a carbon bound to the metal center, implying that the nucleophilic sulfur atom attacks the electrophilic β-carbon on the unsaturated ester.

Cationic Cobalt–Thiolate Complexes for the Dehydrogenative Coupling of nBu3SnH

“…Different from our expectation that the bulky group near to the sulfur moiety would provide the monomeric complex due to steric hindrance, the dimeric complexes 4b and 4c formed again in good yields. The obtained dimeric complexes 4 are air-stable and could be split into mononuclear complexes 5 by treatment with a Lewis base. , For example, the reaction of 4a and excess of 4-methylpyridine in CH 2 Cl 2 at room temperature afforded the corresponding mononuclear complex 5a as a brown solid. All of the cationic dimeric cobalt complexes were fully characterized by multinuclear NMR spectroscopy, mass spectrometry, and cyclic voltammetry (see the Supporting Information for details).…”

Interacción de ARN con doxorrubicina: Influencia del ligando y del metal en la actividad biológica de complejos organometálicos

“…Previous works have studied the relation structure-activity of Iridium(III) families compounds varying the quelating substituents [134], in combination with monodentate ligands [135] and bidentate C,N- [136], N,N- [137,138], N,O- [139], P,O- [140], P,P- [141], P,S- [142], and C,S-ligands [143] or changing the substituents on Cp* [144], but from our knowledge this is the first time in which it is brought to light that every atom of ancillary ligand plays a specific role in the reactivity. Eight half sandwich Iridium complexes have been studied in order to clarify the differences in their biological behaviour and in the mode of binding with DNA and BSA.…”

Targets, Mechanisms and Cytotoxicity of Half-Sandwich Ir(III) Complexes Are Modulated by Structural Modifications on the Benzazole Ancillary Ligand

“…In particular, iridium half-sandwich complexes have aroused considerable interest among the scientific community [9][10][11]. Previous works have studied the structure-activity relationships of iridium(III) families of compounds, modifying the quelating ligands, [12] in combination with mono- [13] and bidentate CˆN- [12,14], NˆN- [12,[14][15][16], NˆO- [17], PˆO- [18], PˆP- [19], CˆS-ligands [20] and OˆC (carbene) [21] or changing the substituents on Cp* in halfsandwich complexes [17,18].…”