Factors Affecting the Formation and Transformation of the Intermediates in Pd(II)-Catalyzed Aromatic C-H Activation: A Comprehensive Study with the Pd(II)/LA Platform.

How the factors affecting the formation and transformation of the intermediates in Pd(II)-catalyzed aromatic C-H activation: A comprehensive study with the Pd(II)/LA platform. Using the Pd(II)/Lewis acid (LA)-catalyzed C-H activation of electron-rich acetanilides as a platform, the C-H activation intermediates, including the precomplex η-intermediate, the agostic hydrogen intermediate, and the palladacycle compound have been well-characterized. This work presents how the catalyst source, substrate, and solvent affect the formation of the η-intermediate and its equilibrium with the agostic hydrogen intermediate, and the transformation of the agostic hydrogen intermediate to the palladacycle compound through C-H activation. The findings disclosed above are provided as a guideline for the catalyst design of the oxidative olefination of acetanilide with dioxygen, and the catalytic efficiency matched well with the mechanistic findings.