2178-03-2Relevant academic research and scientific papers
Rhodium(I)-catalyzed regiospecific dimerization of aromatic acids: Two direct C-H bond activations in water
Gong, Hang,Zeng, Huiying,Zhou, Feng,Li, Chao-Jun
, p. 5718 - 5721 (2015)
2,2'-Diaryl acids are key building blocks for some of the most important and high-performance polymers such as polyesters and polyamides (imides), as well as structural motifs of MOFs (metal-organic frameworks) and biological compounds. In this study, a direct, regiospecific and practical dimerization of simple aromatic acids to generate 2,2'-diaryl acids has been discovered, which proceeds through two rhodium-catalyzed C-H activations in water. This reaction can be easily scaled up to gram level by using only 0.4-0.6 mol% of the rhodium catalyst. As a proof-of-concept, the natural product ellagic acid was synthesized in two steps by this method. On the double: An efficient, regiospecific, and general oxidative dimerization of simple aryl acids to generate diaryl acids was developed. The reaction involves two direct aryl C-H activations catalyzed by rhodium, uses water as the solvent, and can be easily scaled up. The natural product ellagic acid was obtained in only two steps by using this method.
2,2′-Biaryldicarboxylate Synthesis via Electrocatalytic Dehydrogenative C-H/C-H Coupling of Benzoic Acids
Zeng, Zhongyi,Goebel, Jonas F.,Liu, Xianming,Goo?en, Lukas J.
, p. 6626 - 6632 (2021/06/25)
2,2′-Biaryldicarboxylates are important functionalities in bioactive compounds, functional materials, and chiral catalysts. These compounds have been found to be conveniently accessible from benzoic acids via Rh-catalyzed electrooxidative C-H/C-H couplings, giving valuable dihydrogen as the byproduct. In an undivided cell with Pt electrodes, RhCl3·3H2O catalyzes the oxidative carboxylate-directed ortho-homocoupling of various aromatic acids with a current efficiency of 67%. The protocol is operationally simple, tolerates a wide variety of functional groups, and does not require the exclusion of air and moisture. Heterodimerizations via cross-dehydrogenative couplings of naphthyl-1-carboxylic acids with acrylic or benzoic acids were also shown to work.
Bisoxazoline ligands with an axial-unfixed biaryl backbone: the effects of the biaryl backbone and the substituent at oxazoline ring on Cu-catalyzed asymmetric cyclopropanation
Zhang, Wanbin,Xie, Fang,Matsuo, Shigeaki,Imahori, Yuji,Kida, Toshiyuki,Nakatsuji, Yohji,Ikeda, Isao
, p. 767 - 777 (2007/10/03)
The synthesis of novel C2-symmetric bisoxazoline ligands with an axial-unfixed biaryl backbone and different substituents at the oxazoline ring is reported. The diastereomer equilibrium of these ligands in solution and their complexation behavi
