A macrocyclic Pd(II)–Ni(II) complex in Heck and Suzuki reactions

• Pd(II)–Ni(II) macrocyclic complex catalyzes efficiently Heck and Suzuki coupling.
• Pd(II)–Ni(II) macrocyclic complex shows very high stability under reaction conditions.
• Slow release of palladium from the complex is responsible for the catalytic activity.

A heterodinuclear Pd(II)–Ni(II) macrocyclic Schiff base complex was applied as a catalyst for Heck and Suzuki cross-coupling reactions. In reaction of 4-bromoanisole with styrene, 4-methoxy-trans-stilbene was formed as the main product with a yield of up to 87%. In the Suzuki coupling of 4-bromoanisole with PhB(OH)2 in a 2-propanol/water solution, up to 96% of the product was obtained. Analyses of the post-reaction mixtures confirmed the high stability of the macrocyclic Pd(II)–Ni(II) complex under the reaction conditions. The partial decomposition of the complex started at the Ni(II) site.

A heterodinuclear Pd(II)–Ni(II) complex exhibited good catalytic activity in Heck and Suzuki reactions. In the post reaction mixture unchanged complex was identified confirming its high stability. The partial decomposition of the complex during the reaction was observed with release of Pd(II), responsible for the catalytic process.Figure optionsDownload as PowerPoint slide