Arylhydrazone‐Thioeter Palladium Pincer Complexes Catalyzed Carbonylative Suzuki–Miyaura Cross‐Coupling Using Fe(CO)₅ as CO Surrogate

Abstract

A series of Pd(II)‐pincer complexes 3a–d have been synthesized and characterized in good yields, via C–H bond activation on arylhydrazone‐thioether ligands. The investigation of these new Pd(II)‐pincer complexes has proved that the possesses excellent catalytic activity for carbonylative Suzuki–Miyaura cross‐coupling reactions of aryl iodides with arylboronic acids using Fe(CO)5 as carbonyl source. Notably, this strategy offers several advantages such as shorter reaction time, nonrequirement of toxic CO gas, and good to excellent yield of the desired products for wide range of applicable substrate; mainly, carbonylative Suzuki–Miyaura coupling just requires only 0.5 mol% of Pd(II)‐pincer complexes. We have also demonstrated a new efficient route for the synthesis of an antineoplastic agent 4‐(methoxyphenyl)‐(3,4,5‐trimethoxyphenyl)methanone. Additionally, the possible mechanism of this Pd(II)‐pincer complexes process is further supported by the density functional theory (DFT) study.