954-16-5Relevant articles and documents
Oxidative Cleavage of Alkenes by O2with a Non-Heme Manganese Catalyst
Bennett, Elliot L.,Brookfield, Adam,Guan, Renpeng,Huang, Zhiliang,Mcinnes, Eric J. L.,Robertson, Craig M.,Shanmugam, Muralidharan,Xiao, Jianliang
supporting information, p. 10005 - 10013 (2021/07/19)
The oxidative cleavage of C═C double bonds with molecular oxygen to produce carbonyl compounds is an important transformation in chemical and pharmaceutical synthesis. In nature, enzymes containing the first-row transition metals, particularly heme and non-heme iron-dependent enzymes, readily activate O2 and oxidatively cleave C═C bonds with exquisite precision under ambient conditions. The reaction remains challenging for synthetic chemists, however. There are only a small number of known synthetic metal catalysts that allow for the oxidative cleavage of alkenes at an atmospheric pressure of O2, with very few known to catalyze the cleavage of nonactivated alkenes. In this work, we describe a light-driven, Mn-catalyzed protocol for the selective oxidation of alkenes to carbonyls under 1 atm of O2. For the first time, aromatic as well as various nonactivated aliphatic alkenes could be oxidized to afford ketones and aldehydes under clean, mild conditions with a first row, biorelevant metal catalyst. Moreover, the protocol shows a very good functional group tolerance. Mechanistic investigation suggests that Mn-oxo species, including an asymmetric, mixed-valent bis(μ-oxo)-Mn(III,IV) complex, are involved in the oxidation, and the solvent methanol participates in O2 activation that leads to the formation of the oxo species.
Acylboronates in polarity-reversed generation of acyl palladium(II) intermediates
Trofimova, Alina,Holownia, Aleksandra,Tien, Chieh-Hung,?irvinskas, Martynas J.,Yudin, Andrei K.
supporting information, p. 3294 - 3299 (2021/05/07)
We report a catalytic cross-coupling process between aryl (pseudo)halides and boron-based acyl anion equivalents. This mode of acylboronate reactivity represents polarity reversal, which is supported by the observation of tetracoordinated boronate and acyl palladium(II) species by 11B, 31P NMR, and mass spectrometry. A broad scope of aliphatic and aromatic acylboronates has been examined, as well as a variety of aryl (pseudo)halides.
Carbon-wrapped Fe-Ni bimetallic nanoparticle-catalyzed Friedel-Crafts acylation for green synthesis of aromatic ketones
Bao, Shouxin,Hu, Dianwen,Jia, Mingjun,Lei, Zhenyu,Liu, Jingyao,Song, Xiaojing,Sun, Hao,Zhang, Hao,Zhang, Wenxiang,Zhao, Chen
, p. 7943 - 7954 (2021/12/27)
Developing highly efficient and durable eco-friendly heterogeneous catalysts for the Friedel-Crafts acylation (FCA) reaction has been a long-term and significant target, yet remains a great challenge. Herein, a series of Fe-Ni alloy nanoparticles (NPs) encapsulated inside N-doped carbon spheres (FexNi1?x@NC) was rationally fabricated by pyrolyzing the Fe-Ni bimetallic metal-organic frameworks (BMOFs-FexNi1?x) to this end. Various characterization results demonstrated that FeNi alloy NPs (25 nm) covered by a thin carbon shell (5 nm) were uniformly distributed throughout the entire carbon-based composite. A number of oxidized metal species (Fe3+, Ni2+) are present on the surface of the inner bimetallic core, which should be the main source of catalytically active centers of the carbon-wrapped metal NP catalysts. The composition-optimized Fe0.8Ni0.2@NC with relatively higher positive surface charges exhibited the highest catalytic activity and excellent stability for the acylation of aromatic compounds with acyl chlorides. The density functional theory calculations revealed that the catalytic activity of the FexNi1?x@NC catalysts could arise from the electron transfer,i.e., from the outermost layer of the carbon shell to the inner positively charged Fe-based metal NPs, which can lead to a positive charge distribution (by acting as weak Lewis acid sites) on the external surface of the carbon-encapsulated metal NP catalysts. In this case, the external carbon shell can function as ‘chainmail’ to transfer the Lewis acidity (positive charge), and also to protect the inner metal core from the destructive reaction environment, thus resulting in the formation of highly efficient and durable FCA catalysts.
