Theoretical studies on the effect of substituents of the N-heterocycliccarbene ligand present in the Pd-PEPPSI complex on the formationmechanism of the Negishi cross-coupling reaction

Transition metal complexes bearing N-heterocyclic carbene ligands (NHCs) havegained a place of crucial importance in numerous areas of research such asmedicinal chemistry, material sciences, and homogeneous/heterogeneouscatalysis.[۱].Recently, several monoligated Pd–N-heterocyclic carbene (Pd–NHC) complexeshave been prepared and have demonstrated high levels of activity in various Pd-catalyzed crosscouplingreactions, as reported [۲].The increased catalytic activity is attributed to the enhancedsteric bulk of the NHC ligand. While oxidative addition does not seem to be significantlyinfluenced by the sterics, both metal–metal exchange and reductive elimination appear to beaffected[۳]. The main focus of this project is to investigate the effect of NHC ligand side chainsin Pd-PEPPSI complexes. Mechanistic studies on biaryl compounds using Pd-PEPPSI complexesas catalysts in Negishi cross-coupling reactions are being examined. The theoretical resultsobtained in this project demonstrate that the Pd-PEPPSI-iPent catalyst outperforms Pd-PEPPSIiPr,which is consistent with experimental findings. Calculations were conducted using theGaussian۰۹ program with the CAM-B۳LYP/DEF۲-SVP method.

کلیدواژه ها:

Negishi ، Cross-coupling ، Mechanisim