Carbenes and phosphonium ylides: a fruitful association in coordination chemistry

Among a plethora of σ-donor ligands available, carbon-centered ones have become essential, in particular with the emergence of N-heterocyclic carbenes (NHCs), positioning themselves as credible alternatives to traditional nitrogen- and phosphorus-based systems. Phosphonium ylides representing another class of neutral η¹-bonded carbon ligands have also been shown to act as effective Lewis bases. Considering the intrinsic features of the carbene and phosphonium ylide ligands, similar in terms of electronic properties, but different in terms of bonding mode, the design of hybrid systems combining these two types of carbon functionalities appeared to be a natural and exciting challenge. This Perspective comprehensively covers the chemistry of such ligand architectures from synthesis and fundamental aspects to catalytic applications.

Pd/Pt metallacyclopropa[60]fullerene complexes bearing versatile phosphorous ylide ligands; a comprehensive multi-spectroscopic, electrochemistry, theoretical and catalytic studies

The synthesis of new Pd/Pt metallacyclopropa[60]fullerene complexes containing unsymmetrical phosphorus ylides [Ph₂P(CH₂)_nPPh₂ = C(H)C(O)C₆H₄-p-OMe] (n = 1, (Y¹); n = 2, (Y²)) has been reported. The synthesized complexes exhibit different structures, including two P,C- chelated [(η²-C₆₀)Pd(κ²-Y¹)] (1) and [(η²-C₆₀)Pt(κ²-Y¹)] (2) complexes and two P-coordinated [(η²-C₆₀)Pd(Y²)₂] (3) and [(η²-C₆₀)Pt(Y²)₂] (4) complexes with chain structures. Characterization of all compounds was performed by multi-neclear NMR spectroscopies (¹H, ¹³C and ³¹P NMR) and other conventional techniques such as IR, UV-Vis, SEM and cyclic voltammetry (CV) analyses. In this regard, the presence of all characteristic chemical shifts in the IR and NMR spectra proposed the formation of desired products. Also, theoretical studies were used to investigate the nature of metal-ligands in all complexes. In addition, a comparison between the catalytic activity of Pd complexes 1 and 3 was evaluated in the Suzuki-Miyaura reaction of various aryl chlorides with phenylboronic acid, which revealed a meaningful difference between the catalytic activity of complexes 1 and 3.

Zwitterionic phosphonium ligands: synthesis, characterization and application in telomerization of 1,3-butadiene

Novel zwitterionic phosphonium alkylsulfonate ligands are chemoselectively synthesized from N-heterocyclic phosphines and cyclic sulfones in one step in good to excellent yields.

P,C-Chelation versus P,P-coordination of unsymmetrical phosphorus ylides in palladacyclopropa[60]fullerene complexes; synthetic, spectroscopic, and theoretical studies

New palladacyclopropa[60]fullerene complexes containing P,C-chelated and P,P-coordinated unsymmetrical phosphorus ylides were synthesized and characterized successfully.