A green route to platinum N-heterocyclic carbene complexes: mechanism and expanded scope

Abstract

A sustainable and facile weak-base synthetic route to platinum N-heterocyclic carbene (NHC) complexes is disclosed.

Advances in the Synthesis and Applications of N-Heterocyclic Carbene Metal Complexes with a Focus on the Weak Base Route

“…Despite the use of Pt-NHC complexes in medicinal chemistry and catalysis, there are few reports dealing with the simple and facile synthetic assembly of the compounds. The weak base route to [Pt­(NHC)­(SMe 2 )­Cl 2 ] complexes was first reported by Nolan in 2020 and then expanded upon in 2022, as will be discussed in a following paragraph. , The reaction is similar to the reported procedure for gold complexes. More specifically, upon heating in acetone for 20 h, 13 Pt­(II)-NHC complexes were isolated in good to excellent yields (Scheme and Table ).…”

“…The conditions used for the preparation of Pt­(II)-NHC derivatives proved unexpectedly suitable for the synthesis of zerovalent platinum complexes of general formula [Pt­(NHC)­(dvtms)], using the same battery of saturated or unsaturated imidazolium salts and [Pt 2 (dvtms) 3 ] in the presence of potassium carbonate in air . To showcase the usefulness of this simple synthetic procedure, the well-defined Pt­(II) and Pt(0) complexes were tested as precatalysts in the aerobic and solventless hydrosilylation of 1-octene with 1,1,1,3,5,5,5-heptamethyltrisiloxane.…”

“…As for the platinum chemistry, as presented in a previous section, Nahra, Nolan, and Cazin have recently reported a wide scope of novel Pt­(II)-NHC and Pt(0)-NHC complexes bearing thioether (dimethylsulfide and tetrahydrothiophene) or 1,3-divinyltetramethyldisiloxane (dvtms) ligands, respectively (Scheme ). , …”

Platinum(0)-η2-1,2-(E)ditosylethene Complexes Bearing Phosphine, Isocyanide and N-Heterocyclic Carbene Ligands: Synthesis and Cytotoxicity towards Ovarian and Breast Cancer Cells

“…One of the key features of platinum alkene complexes is their versatility in catalyzing different organic reactions, including hydrogenation, hydroamination and polymerization reactions [ 15 , 16 , 17 ]. The ability of platinum to engage in oxidative addition and reductive elimination processes allows these complexes to participate in catalytic cycles with high efficiency.…”

Platinum(terpyridine) complexes with N-heterocyclic carbene co-ligands: high antiproliferative activity and low toxicityin vivo

“…9 Two well-established ligand systems which form stable complexes with Pt and other metal centres are the N-heterocyclic carbenes (NHC) and 2,2′:6′,2′′-terpyridine (tpy) ligands. 10,11 The large, fused ring aromatic scaffold of the tpy ligands allows for DNA intercalation, 12–14 and makes the compounds themselves bioactive as inhibitors of topoisomerase. 15–17 Therefore, Pt(tpy) complexes can be considered as multimodal anticancer agents, 18 with both the Pt centre and the tpy ligand exhibiting bioactivity.…”