Palladium-Catalyzed Intramolecular C-H Arylation versus 1,5-Palladium Migration: A Theoretical Investigation.

Theoretical investigations were carried out to elucidate the origin of chemoselectivity in the palladium-catalyzed reactions of 2-(dimethylphenylsilyl)phenyl triflates with or without an amino group at the 3-position. The selective formation of a 5,10-dihydrophenazasiline rather than a dibenzosilole from the substrate with an amino group at the 3-position could be successfully explained by proposing a new 1,5-palladium migration pathway that involves a neutral diorganopalladium(II) intermediate along with the subsequent formation of a low-energy amine-coordinated palladacycle intermediate prior to the C-N bond-forming process.