A highly recoverable polymer-supported ionic salen-palladium complex as a catalyst for the Suzuki-Miyaura cross coupling in neat water

Publication date: Available online 27 November 2017 Source:Journal of Organometallic Chemistry Author(s): Kamlesh Rudreshwar Balinge, Avinash Ganesh Khiratkar, Pundlik Rambhau Bhagat A polymer supported Pd-salen complex (PS-Pd-salen) was synthesized and characterized by Fourier transform infrared spectroscopy (FT-IR), Fourier-transform NMR spectroscopy (FT-NMR), thermal gravimetric analysis (TGA), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), surface area and pore size distribution by Brunauer-Emmett-Teller (BET). The heterogeneous catalytic performance of the PS-Pd-salen for the Suzuki-Miyaura coupling of variety of phenyl boronic acid with different aryl halides was successfully conducted in water with K2CO3 and 20 mg catalyst loading at room temperature. The coupling reactions with aryl iodides and bromides were achieved at room temperature with good to excellent yield; whereas the reactions with aryl chlorides were performed in aqueous-ethanol (1:1) at 90 °C. The product yields related with the substrates were optimized, and main reaction factors influencing the yields were also recognized. The results clearly indicated that the reaction constraints needed to achieve high yields are substrate-reliant. The hot filtration test verified heterogeneous nature of PS-Pd-salen complex. Moreover, the catalyst showed excellent reusability for five successive runs in slight compromising with its activity. Graphical abstract

Source: Journal of Organometallic Chemistry - November 27, 2017 Category: Chemistry Source Type: research