22357-57-9Relevant articles and documents
Stepwise benzylic oxygenation via uranyl-photocatalysis
Hu, Deqing,Jiang, Xuefeng
supporting information, p. 124 - 129 (2022/01/19)
Stepwise oxygenation at the benzylic position (1°, 2°, 3°) of aromatic molecules was comprehensively established under ambient conditions via uranyl photocatalysis to produce carboxylic acids, ketones, and alcohols, respectively. The accuracy of the stepwise oxygenation was ensured by the tunability of catalytic activity in uranyl photocatalysis, which was adjusted by solvents and additives demonstrated through Stern–Volmer analysis. Hydrogen atom transfer between the benzylic position and the uranyl catalyst facilitated oxygenation, further confirmed by kinetic studies. Considerably improved efficiency of flow operation demonstrated the potential for industrial synthetic application.
Palladium-Aminopyridine Catalyzed C?H Oxygenation: Probing the Nature of Metal Based Oxidant
Lubov, Dmitry P.,Bryliakova, Anna A.,Samsonenko, Denis G.,Sheven, Dmitriy G.,Talsi, Evgenii P.,Bryliakov, Konstantin P.
, p. 5109 - 5120 (2021/11/10)
A mechanistic study of direct selective oxidation of benzylic C(sp3)?H groups with peracetic acid, catalyzed by palladium complexes with tripodal amino-tris(pyriylmethyl) ligands, is presented. The oxidation of arylalkanes having secondary and tertiary benzylic C?H groups, predominantly yields, depending on the substrate and conditions, either the corresponding ketones or alcohols. One of the three 2-pyriylmethyl moieties, which is pending in the starting catalyst, apparently, facilitates the active species formation and takes part in stabilization of the high-valent Pd center in the active species, occupying the axial coordination site of palladium. The catalytic, as well as isotopic labeling experiments, in combination with ESI-MS data and DFT calculations, point out palladium oxyl species as possible catalytically active sites, operating essentially via C?H abstraction/oxygen rebound pathway. For the ketones formation, O?H abstraction/в-scission mechanism has been proposed.
Non-Heme-Type Ruthenium Catalyzed Chemo- and Site-Selective C?H Oxidation
Doiuchi, Daiki,Nakamura, Tatsuya,Hayashi, Hiroki,Uchida, Tatsuya
supporting information, p. 762 - 765 (2020/03/05)
Herein, we developed a Ru(II)(BPGA) complex that could be used to catalyze chemo- and site-selective C?H oxidation. The described ruthenium complex was designed by replacing one pyridyl group on tris(2-pyridylmethyl)amine with an electron-donating amide ligand that was critical for promoting this type of reaction. More importantly, higher reactivities and better chemo-, and site-selectivities were observed for reactions using the cis-ruthenium complex rather than the trans-one. This reaction could be used to convert sterically less hindered methyne and/or methylene C?H bonds of a various organic substrates, including natural products, into valuable alcohol or ketone products.
