22699-70-3Relevant articles and documents
Selective electrochemical oxidation of aromatic hydrocarbons and preparation of mono/multi-carbonyl compounds
Li, Zhibin,Zhang, Yan,Li, Kuiliang,Zhou, Zhenghong,Zha, Zhenggen,Wang, Zhiyong
, p. 2134 - 2141 (2021/09/29)
A selective electrochemical oxidation was developed under mild condition. Various mono-carbonyl and multi-carbonyl compounds can be prepared from different aromatic hydrocarbons with moderate to excellent yield and selectivity by virtue of this electrochemical oxidation. The produced carbonyl compounds can be further transformed into α-ketoamides, homoallylic alcohols and oximes in a one-pot reaction. In particular, a series of α-ketoamides were prepared in a one-pot continuous electrolysis. Mechanistic studies showed that 2,2,2-trifluoroethan-1-ol (TFE) can interact with catalyst species and generate the corresponding hydrogen-bonding complex to enhance the electrochemical oxidation performance. [Figure not available: see fulltext.]
Photoredox-Catalysis-Modulated, Nickel-Catalyzed Divergent Difunctionalization of Ethylene
Li, Jiesheng,Luo, Yixin,Cheo, Han Wen,Lan, Yu,Wu, Jie
supporting information, p. 192 - 203 (2019/01/21)
Divergent synthesis that enables a catalytic reaction to selectively produce different products from common substrates will allow the charting of wider chemical space and the unveiling of distinct mechanistic paradigms. A common strategy for it employs different ligands to modulate organometallic catalysts. Dramatic developments in photocatalysis have enabled previously inaccessible transformations. In particular, photoredox catalysis modulates the oxidation state of transition-metal complexes, offering enormous opportunities for methodology development. Herein, we developed a photo-mediated divergent ethylene difunctionalization via modulating oxidation states of the nickel catalyst by using different photoredox catalysts. This work will inspire new perspectives for value-added chemical synthesis using ethylene as a feedstock and shed light on photoredox-catalyst-based divergent synthesis, which fundamentally differs from ligand-controlled transition-metal catalysis.Divergent synthesis represents a powerful strategy for directly accessing different molecular scaffolds originating from the same starting materials. Access to different end products via transition-metal catalysis is conventionally achieved by ligand control. We herein demonstrate the use of ethylene feedstock and commercially available aryl halides to accomplish the divergent synthesis of 1,2-diarylethanes, 1,4-diarylbutanes, or 2,3-diarylbutanes in a highly selective fashion through the synergistic combination of nickel and photoredox catalysis. Mechanistic studies suggest that the observed selectivity was due to different active states of Ni(I) and Ni(0) modulated by Ru- and Ir-based photoredox catalysts, respectively. The ability to access different organometallic oxidation states via photoredox catalysis promises to inspire new perspectives for synergistic transition-metal-catalyzed divergent synthesis.Functionalization of ethylene without polymerization is challenging under photo-irradiation conditions. We have demonstrated that the photo-transformation of ethylene can be controllable by merging photoredox and transition-metal catalysis. In our study, the use of different photoredox catalysts was able to modulate the oxidation state of the nickel catalyst. Through different oxidation states, the nickel-catalyzed couplings proceeded via distinct pathways to generate divergent ethylene difunctionalization products selectively from the same feedstock.
Method for directly oxidizing benzyl-position C-H bond into ketone
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Paragraph 0084-0087, (2017/08/29)
The invention discloses a method for directly oxidizing a benzyl-position C-H bond into ketone, wherein aryl ethyl compounds are catalyzed and oxidized by nitrite ester; a synergistic catalytic system of free radical initiator and nitrite ester is adopted, and a catalytic system of non-metallic catalyst and oxygen is adopted, the oxidization of the C-H bond of a free radical-activated aryl side chain is simple in operation; after completing the reaction, petroleum ether/ethyl acetate at a volume ratio of (50-1):1 is used as an eluent; column chromatography separation is performed to obtain a target product. The catalytic system in the invention uses oxygen as an oxygen source and has high atomic economy; the invention is a non-metallic catalytic system and provides a novel method for avoid metal residues in synthetic drugs; for diethyl aromatic hydrocarbon, the method provided by the invention can be adopted to selectively oxidize diethyl aromatic hydrocarbon into monoketone and diketone; the method of the invention can be adopted to efficiently synthesize tranquillizer lenperone, so that a novel method for synthesizing lenperone is provided.
