Synthesis, Characterization and Preliminary Catalytic Activity of Five-membered Chelate Salen-Palladium(II) Complexes Toward Mizoroki-Heck Reaction

Abstract

Abstract: Two reliable and economical Salen-palladium(II) complexes,N,N’-bis(4-methoxy-salicylidene)propane- 1,2-diaminepalladium (II) (MSB-1), and N,N’-bis(4-methyl-alpha-salicylidene)propane-1,2-diaminepalladium(II) (MSB-2) have been successfully synthesized via complexation reaction between Schiff base ligands (LSB-1 and LSB-2) with palladium(II) acetate, respectively. The synthesized compounds were successfully characterized using several types of analytical and spectroscopic methods such as CHN elemental analyses, FTIR spectroscopy, and NMR spectroscopy. Previously, most of researchers highlighted the used of metal phosphine complex as an efficient catalyst for carbon-carbon bond formation of Mizoroki-Heck reaction. However, due to the air, moisture-labile and the high cost of phosphine ligand compared to palladium metal itself, there is an urge in the search of alternative cheap and relatively stable phosphine-free catalysts that could offered comparable activity. The synthesized catalysts were introduced and subjected to the Mizoroki- Heck. The performances of catalytic activity were monitored by GC-FID at 3 hours reaction period. Preliminary results showed that the percentage conversion of 4-bromonitrobenene to the coupled products were 100% indicated that MSB-1 and MSB-2 can act ideal potential catalysts in the Mizoroki-Heck reaction.