936-99-2Relevant articles and documents
Carbonyl 1,2-transposition through triflate-mediated a-amination
Wu, Zhao,Xu, Xiaolong,Wang, Jianchun,Dong, Guangbin
, p. 734 - 740 (2021/11/16)
To date, it remains challenging to selectively migrate a carbonyl oxygen within a given molecular scaffold, especially to an adjacent carbon. In this work, we describe a simple one- or two-pot protocol that transposes a ketone to the vicinal carbon. This approach first converts the ketone to the corresponding alkenyl triflate, which can then undergo the palladium- and norbornene-catalyzed regioselective a-amination and ipso-hydrogenation enabled by a bifunctional hydrogen and nitrogen donor. The resulting "transposed enamine" intermediate can subsequently be hydrolyzed to produce the 1,2-carbonyl-migrated product. This method allows rapid access to unusual bioactive analogs through late-stage functionalization.
Efficient Aliphatic C-H Oxidation and C═C Epoxidation Catalyzed by Porous Organic Polymer-Supported Single-Site Manganese Catalysts
Wang, Bingyang,Lin, Jin,Sun, Qiangsheng,Xia, Chungu,Sun, Wei
, p. 10964 - 10973 (2021/09/08)
Bioinspired manganese complexes have emerged over recent decades as attractive catalysts for a number of selective oxidation reactions. However, these catalysts still suffer from oxidative degradation. In the present study, we prepared a series of porous Mn-N4 catalysts in which the catalytic units are embedded in the skeleton of porous organic polymers (POPs). These POP-based manganese catalysts demonstrated high reactivity in the oxidation of aliphatic C-H bonds and the asymmetric epoxidation of olefins. Furthermore, these catalysts could be readily recycled and reused due to their heterogeneous nature. Morphological characterization revealed that the Mn-N4 complex was individually distributed over a porous polymer network. Remarkably, the nature of the single-site catalyst prevented oxidative degradation during the reaction. The present work has thus developed a successful approach for bioinspired single-site manganese catalysts in which the oxidation reaction is confined to a specific channel in an enzyme-like mode.
Sonochemical Preparation of Dipicolinamide Mn-complexes and Their Application as Catalysts Towards Sono-synthesis of Ketones
Arafa, Wael A. A.
, p. 1403 - 1412 (2019/02/25)
A series of non-heme Mn-complexes has been synthesized by the sonication of manganese (II)chloride and bis-amides (condensation products of 2-picolinic acid and o-phenylenediamines). The Mn-complexes effectively promote the oxidation of unactivated aliphatic and benzylic C─H and N-bearing heterocycles substrates with low catalyst loading using eco-friendly hydrogen peroxide in the presence of acetic acid as additive under ultrasonic irradiation. Chromatographic studies revealed that the corresponding ketones are the only detectable products. Noteworthy, the presence of electron donors in the catalyst structure significantly increased the reaction yields. The substantial lowering of the oxidation reaction yields by adding ionol (2,6-di-tert-butyl-4-methylphenol) as a free radical trap suggesting a free radical reaction pathway.
