An operationally simple and atom-economical method for the E-selective preparation of enol ethers is described. A novel dicarbonyl(5-phenyldipyrrinato)rhodium complex, 2, was prepared in four synthetic steps, characterized by X-ray crystallography and NMR spectroscopy, and then investigated as a catalyst for the intermolecular hydroalkoxylation of terminal alkynes. Solvent and substrate studies were used to gain insight into the mechanism of the reaction. Cyclic voltammetry was also used to investigate the electronic properties of 2. The rhodium(I)-catalyzed intermolecular alkyne hydroalkoxylation reaction reported here mediates excellent substrate transformation with a high degree of E/Z selectivity which is opposite to that reported previously using alternative catalysts.

N,N'-Asymmetrically substituted, methylene-linked bis(imidazol-2-ylidene) complexes have been prepared subsequent to a selective synthesis of the bis(imidazolium) salt precursors involving the quarternisation of N-alkyl and -aryl imidazoles with N-halomethyl imidazolium salts. The adaptability of the ligand precursor synthesis is illustrated through access to the N-Me/N'-Mes and N-Mes/N'-2,6-(i-Pr)2Ph systems, leading to the Pd(II) complexes [{(MeIm)(MesIm)CH2}Pd(L)2](n+), L = Cl/I (n = 0) and NCMe (n = 2), and [{(MesIm)[2,6-(i-Pr)2PhIm]CH2}Pd(L)2], L = Cl/I. The dicationic hybrid N,N'-alkyl/aryl complex was inactive in the copolymerisation of ethylene/carbon monoxide, displaying reactivity akin to N,N'-dialkyl analogues.