Through-space intramolecular palladium rearrangement in substituted aryl complexes: theoretical study of the aryl to alkylpalladium migration process.

摘要: DFT/B3LYP calculations have been carried out to study intramolecular 1,n palladium shifts (n = 3−5) between sp2 and sp3 carbon atoms in alkylarylpalladium systems. Such shifts, which also involve a concomitant exchange with hydrogen atom of the alkylaryl ligand, are quite often pivotal step several organic transformations mediated by complexes. We show that intimate mechanism for 1,3 shift corresponds Pd(IV) pathway, whereas Pd(II) pathway is favored case 1,5 migrations. In 1,4 migrations, both mechanisms competitive. The can either true intermediate (oxidative addition/reductive elimination mechanism) or transition state migration mechanism). energy barrier very high shift, making this process unlikely, contrast other ones enthalpy barriers ranging 22.8 kcal mol-1 (for shift) 31.9 least favorab...