Catalytic activity of a palladium(ii) complex modified on multi-wall carbon nanotubes: an efficient catalyst for the Suzuki cross-coupling reaction

Abstract

We synthesized a Pd(II)-containing multi-wall carbon nanotube (MWCNT) catalyst (Pd(II)/MWCNT catalyst). It showed excellent activity in catalyzing the asymmetric Suzuki–Miyaura coupling reaction with high stereoselectivity. The eclipsed structure of the Pd complex provided a chiral environment to achieve the asymmetric Suzuki–Miyaura coupling reaction. High-performance liquid chromatography using chiral columns was conducted to examine the axial chiral products generated through these reactions. The fabricated nano catalyst was characterized using Fourier transform infrared spectroscopy, X-ray diffraction analysis, scanning electron microscopy, thermogravimetric analysis, energy-dispersive X-ray spectroscopy, inductively coupled plasma-atomic emission spectroscopy (ICP-AES), and Brunauer–Emmett–Teller theory. Pd(II)/MWCNT selectively and efficiently catalyzed the large-scale synthesis of target molecules with high yields and large cycle numbers. The catalyst could be recycled up to seven runs without a noticeable loss of activity and was very stable. ICP-AES showed that leaching of Pd complex did not occur during recycling of the Pd(II)/MWCNT nano catalyst.