The mechanism of the Cu(i)-catalyzed domino reaction furnishing 1-aryl-1,2,3-triazole assisted by CuI and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) is explored with density functional theory (DFT) calculations.
The oxidative addition of 4-substituted iodobenzenes on Pd(0)-PMe3 complexes has been studied at the BP86 level of theory including dispersion correction and solvation effect, with tetrahydrofuran as solvent. The bisphosphine pathway was found to be barrierless, whereas the monophosphine route is hampered by the high dissociation energy of trimethylphosphine. The reaction free energy of this step shows linear correlation with the Hammett constants of the para substituents with the most electron withdrawing groups being the most exergonic.
DFT computations reveal different reaction mechanisms for the oxidative addition of C(sp2)–F and C(sp3)–F bonds to the Al(i) complexes: a concerted mechanism for C(sp2)–F and a stepwise mechanism for C(sp3)–F involving fluoride transfer and the formation and recombination of an ion pair.
Cooperative Metal + Ligand Oxidative Addition and σ-Bond Metathesis: A DFT Study