Xn:Harmful;86-26-0Relevant articles and documents
Preparation and characterization of new palladium complex immobilized on (chitosan)/PoPD biopolymer and its catalytic application in Suzuki cross-coupling reaction
Seyedi, Neda,Zahedifar, Mahboobeh
, (2021/11/17)
The present work reports the design, synthesis, and characterization of palladium complex immobilized on chitosan/poly(o-phenylenediamine) (CS-PoPD-Pd) for the catalytic application in the Suzuki–Miyaura C-C cross-coupling reaction through a nontoxic, inexpensive, eco-friendly, and practical method. Fourier-transform–infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), elemental mapping, X-ray diffraction (XRD), and inductively coupled plasma-optical emission spectrometry (ICP-OES) techniques were used for analyzing the prepared catalyst. Characterization studies showed that CS-PoPD-Pd was successfully synthesized according to our design. CS-PoPD-Pd composite demonstrated high product yield and high turnover number (TON) and turnover frequency (TOF) values with small catalyst loading for the Suzuki–Miyaura C-C cross-coupling reaction under mild reaction conditions. Besides, the synthesized CS-PoPD-Pd composite could be readily recycled and reused for at least five runs without discernible loss of its catalytic activity.
Aromatization as the driving force for single electron transfer towards C-C cross-coupling reactions
Adhikari, Debashis,Dey, Dhananjay,Kundu, Abhishek,Pal, Subhankar,Roy, Monojit
, p. 1934 - 1940 (2022/04/07)
There is a strong current interest in C-H functionalization reactions under metal-free conditions. We report herein the deprotonated form of dihydrophenazine (DPh) as a potent initiator under photochemical conditions that can efficiently generate aryl radicals via single electron transfer (SET). The driving force for such electron transfer is the gain in aromaticity for the initiator molecule. Using this methodology, a series of arenes and heteroarenes have been cross-coupled with aryls at room temperature. Photochemical activation of DPh anions and the subsequent electron transfer to substrate aryldiazonium salts have been proved by Stern-Volmer kinetic analysis. Detailed mechanistic studies including interception of important reaction intermediates prove the aromaticity-driven SET as the key step to generate aryl radicals towards radical-promoted cross-coupling reactions.
Porous Organic Phenanthroline-Based Polymer as an Efficient Transition-Metal-Free Heterogeneous Catalyst for Direct Aromatic C?H Activation
Tang, Yongquan,Chen, Fang,Wang, Sai,Sun, Qi,Meng, Xiangju,Xiao, Feng-Shou
supporting information, p. 8684 - 8688 (2021/05/25)
Direct C?H bond transformation has been regarded as one of the most important areas in organic synthesis in both academia and industry. However, the heterogeneous transition-metal-free catalysis of direct C?H bond transformation has remained a contemporary challenge. To tackle this challenge, we designed and constructed a porous phenanthroline-based polymer (namely POP-Phen) via free radical polymerization of vinyl-functionalized phenanthroline monomers. POP-Phen shows excellent catalytic performances in transition-metal-free catalyzed C?H arylation, even better than those of the corresponding homogeneous catalyst, which is mainly attributed to the high density of catalytically active sites in the heterogeneous catalyst. Kinetic isotope experiments and spectral characterizations demonstrate the electron-transfer between the heterogeneous catalyst and the base (t-BuOK), a key step for C?H activation. We believe that this porous organic phenanthroline polymer could open a new door for the design of novel heterogeneous transition-metal-free catalysts for direct C?H activation.
