Efficient and Recyclable Solid-Supported Pd(II) Catalyst for Microwave-Assisted Suzuki Cross-Coupling in Aqueous Medium

Abstract

Solid-supported catalysts play efficient and crucial roles in organic synthesis. A solid-supported palladium(II) complex based on chitosan was synthesized and fully characterized using all possible tools (Fourier transform infrared spectroscopy, thermogravimetry analysis, differential scanning calorimetry, X-ray photoelectron spectroscopy, energy-dispersive X-ray spectroscopy, inductively coupled plasma atomic emission spectrometry, scanning electron microscopy, transmission electron microscopy, and Brunauer–Emmett–Teller analysis). The catalytic activity of the solid-phase catalyst in Suzuki cross-coupling reactions was evaluated in aqueous solvents under both conventional heating and microwave irradiation conditions. The recyclability and thermal stability of the prepared catalyst were also examined, and the catalyst was found to be active till five consecutive runs without a notable loss of activity under the microwave condition, with the turnover number and turnover frequency values reaching 19,019 and 114,114 h –1 , respectively.

Palladium incorporated MIL-101(Cr): a heterogeneous and reusable catalyst for the C–H functionalization of unactivated arenes

“…A slight shift to a lower value of the >CN– peak signifies the coordination of the imine-N to the Pd. 13 Fig. 1d shows the FT-IR spectrum of reused catalyst IV , which is consistent with the fresh one, indicating that the functional groups of the MOF were retained after five consecutive runs.…”

Pd@l-asparagine–EDTA–chitosan: a highly effective and reusable bio-based and biodegradable catalyst for the Heck cross-coupling reaction under mild conditions

“…Finally, the activated form of the catalyst 1 is recovered by the reductive elimination of HI using K 2 CO 3 base (Scheme 2). 117–119…”

“…Finally, the activated form of the catalyst 1 is recovered by the reductive elimination of HI using K 2 CO 3 base (Scheme 2). [117][118][119] 3.4. Reusability of the Pd@ASP-EDTA-CS catalyst (1) One of the vital parameters in heterogeneous catalytic processes is the reusability of catalyst.…”

Supramolecular Pd@methioine-EDTA-chitosan nanocomposite: an effective and recyclable bio-based and eco-friendly catalyst for the green Heck cross-coupling reaction under mild conditions

“…Finally, the activated form of the catalyst 1 is recovered by the reductive elimination of HI using K 2 CO 3 base (Scheme 2). 132–134…”

“…Finally, the activated form of the catalyst 1 is recovered by the reductive elimination of HI using K 2 CO 3 base (Scheme 2). [132][133][134] 3.4. Reusability of the Pd@MET-EDTA-CS catalyst (1) in HCR Reusability of the heterogeneous catalytic systems is one of the main parameters for a specic process.…”