Mechanistic Study of Direct Arylation of Indole Using Differential Selectivity Measurements: Shedding Light on the Active Species and Revealing the Key Role of Electrophilic Substitution in the Catalytic Cycle

Differential selectivity of the direct arylation of indole with aryl halides under competing and noncompeting conditions with a varying set of reaction parameters was determined using phase trajectories. The results described herein allow for conclusions to be drawn regarding the character of active complexes (cationic, neutral, or anionic) as well as realization of the indole electrophilic substitution in the catalytic cycle using the ligand-free catalytic system