2987-16-8Relevant articles and documents
Selective hydrogenation of 3,3-dimethylbutanoyl chloride to 3,3-dimethylbutyraldehyde with silica supported Pd nanoparticle catalyst
Li, Sifang,Chen, Guoqin,Sun, Lan
, p. 813 - 816 (2011)
A novel method for selective hydrogenation of 3,3-dimethylbutanoyl chloride (DMBC) to 3,3-dimethylbutyraldehyde (DMBA) with silica supported Pd nanoparticle catalyst (Pd/SiO2) is developed. The catalysts were characterized by Fourier transform infrared spectroscopy, X-ray powder diffraction, N2 physisorption and transmission electron microscopy. The performance of the Pd/SiO2 catalyst was compared with Pd/C and Pd/BaSO4 catalysts with or without being pretreated by quinoline-sulfur. The Pd/SiO2 catalyst activated at 80 °C by bubbling hydrogen in cyclohexane for 1 h showed the highest yield of DMBA. For 3 wt.% Pd/SiO2, the yield of DMBA reached 84.6%, which exhibited much higher value than Pd/C and Pd/BaSO4 catalysts.
Zimmerman,A.H. et al.
, p. 7203 - 7209 (1977)
The formyloxyl radical: Electrophilicity, C-H bond activation and anti-Markovnikov selectivity in the oxidation of aliphatic alkenes
Iron, Mark A.,Khenkin, Alexander M.,Neumann, Ronny,Somekh, Miriam
, p. 11584 - 11591 (2020/11/23)
In the past the formyloxyl radical, HC(O)O, had only been rarely experimentally observed, and those studies were theoretical-spectroscopic in the context of electronic structure. The absence of a convenient method for the preparation of the formyloxyl radical has precluded investigations into its reactivity towards organic substrates. Very recently, we discovered that HC(O)O is formed in the anodic electrochemical oxidation of formic acid/lithium formate. Using a [CoIIIW12O40]5- polyanion catalyst, this led to the formation of phenyl formate from benzene. Here, we present our studies into the reactivity of electrochemically in situ generated HC(O)O with organic substrates. Reactions with benzene and a selection of substituted derivatives showed that HC(O)O is mildly electrophilic according to both experimentally and computationally derived Hammett linear free energy relationships. The reactions of HC(O)O with terminal alkenes significantly favor anti-Markovnikov oxidations yielding the corresponding aldehyde as the major product as well as further oxidation products. Analysis of plausible reaction pathways using 1-hexene as a representative substrate favored the likelihood of hydrogen abstraction from the allylic C-H bond forming a hexallyl radical followed by strongly preferred further attack of a second HC(O)O radical at the C1 position. Further oxidation products are surmised to be mostly a result of two consecutive addition reactions of HC(O)O to the CC double bond. An outer-sphere electron transfer between the formyloxyl radical donor and the [CoIIIW12O40]5- polyanion acceptor forming a donor-acceptor [D+-A-] complex is proposed to induce the observed anti-Markovnikov selectivity. Finally, the overall reactivity of HC(O)O towards hydrogen abstraction was evaluated using additional substrates. Alkanes were only slightly reactive, while the reactions of alkylarenes showed that aromatic substitution on the ring competes with C-H bond activation at the benzylic position. C-H bonds with bond dissociation energies (BDE) ≤ 85 kcal mol-1 are easily attacked by HC(O)O and reactivity appears to be significant for C-H bonds with a BDE of up to 90 kcal mol-1. In summary, this research identifies the reactivity of HC(O)O towards radical electrophilic substitution of arenes, anti-Markovnikov type oxidation of terminal alkenes, and indirectly defines the activity of HC(O)O towards C-H bond activation.
Synthesis technology used for preparing 3, 3-dimethylbutyraldehyde through micro-channel reaction
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Paragraph 0039-0046, (2019/10/10)
The invention belongs to the technical field of organic synthesis, and more specifically relates to synthesis technology used for preparing 3, 3-dimethylbutyraldehyde through micro-channel reaction. According to the synthesis technology, reaction is carried out in two micro-channel reactors connected in series; in a first micro-channel reactor, chloro-tert-butane and vinyl acetate are taken a raw materials, aluminium trichloride-dichloromethane system is taken as a catalyst to perform synthesis reaction, a reaction product is introduced into a second micro-channel reactor for mixing with OR water for hydrolysis reaction, an obtained hydrolysis product is subjected to extraction separation so as to obtain a 3, 3-dimethylbutyraldehyde crude product, and rectification is adopted to prepare the pure 3, 3-dimethylbutyraldehyde. The synthesis technology is scientific and reasonable; reaction condition accurate control is realized; synthesis is simple and convenient; production cost is low; purity is 99.5% or higher; the synthesis process is friendly to the environment; and the purity is high.
Preparation method for key intermediate of neotame--3,3-dimethylbutyraldehyde
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Paragraph 0030-0031, (2018/12/02)
The invention provides a preparation method for key intermediate of neotame--3,3-dimethylbutyraldehyde, comprising the following steps: under nitrogen protection in a vessel, organic solvent and a solid acid catalyst are added, tert-butyl chloride and aryl acid vinyl esters are dropped; through a thermal insulation reaction, the catalyst is filtered, the organic layer is decompressed and distilled, and alkali or acid is added for heating, backflow and hydrolysis to produce a crude product to be rectified to produce the final 3,3-dimethylbutyraldehyde product. The preparation method for the keyintermediate of neotame--3,3-dimethylbutyraldehyde has the advantages of low material cost and simple operation, moderate reaction conditions and less side reactions and is safe, environmentally friendly and beneficial for industrial production.
