1550-35-2Relevant academic research and scientific papers
A Convenient Synthesis of Fluorobenzaldehydes by KF/Ph4PBr/18-Crown-6 Reagent System
Yoshida, Yasuo,Kimura, Yoshikazu
, p. 1355 - 1358 (1988)
4-Fluorobenzaldehyde was easily synthesized from 4-chlorobenzaldehyde by potassium fluoride in the presence of tetraphenylphosphonium halide plus 18-crown-6 or poly(ethylene glycol) dimethyl ether.Several fluorobenzaldehyde derivatives were similarly prepared from the corresponding chloro-derivatives in good yields.
Method for efficiently synthesizing fluorine-containing compound
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Paragraph 0061-0063, (2021/06/26)
The invention discloses a method for efficiently synthesizing a fluorine-containing compound, and relates to the field of fluorine-containing compound synthesis. The method is a method for generating a corresponding fluorine atom substituted fluorine-containing compound by reacting aromatic chloride or activated chloride serving as a raw material with potassium fluoride under the action of a novel catalyst. The method disclosed by the invention has the advantages of good product selectivity, high efficiency, mild reaction conditions, simplicity and convenience in operation, convenience in application and the like.
Rhodium-catalyzed reductive carbonylation of aryl iodides to arylaldehydes with syngas
Chen, Suqing,Liu, Zhenghui,Mu, Tiancheng,Wang, Peng,Yan, Zhenzhong,Yu, Dongkun,Zhao, Xinhui
, p. 645 - 656 (2020/05/14)
The reductive carbonylation of aryl iodides to aryl aldehydes possesses broad application prospects. We present an efficient and facile Rh-based catalytic system composed of the commercially available Rh salt RhCl3·3H2O, PPh3 as phosphine ligand, and Et3N as the base, for the synthesis of arylaldehydes via the reductive carbonylation of aryl iodides with CO and H2 under relatively mild conditions with a broad substrate range affording the products in good to excellent yields. Systematic investigations were carried out to study the experimental parameters. We explored the optimal ratio of Rh salt and PPh3 ligand, substrate scope, carbonyl source and hydrogen source, and the reaction mechanism. Particularly, a scaled-up experiment indicated that the catalytic method could find valuable applications in industrial productions. The low gas pressure, cheap ligand and low metal dosage could significantly improve the practicability in both chemical researches and industrial applications.
Direct formylation of fluorine-containing aromatics with dichloromethyl alkyl ethers
Warashina, Takuya,Matsuura, Daisuke,Kimura, Yoshikazu
, p. 587 - 593 (2019/07/22)
Formylations of fluorine-containing aromatic compounds with dichloromethyl alkyl ethers have been investigated. Dichloromethyl propyl ether and dichloromethyl butyl ether have been applied for the formylation of fluorine-containing anisoles to give the corresponding aldehydes in good yields. Application of these ethers is preferable to that of methyl ether, which is prepared from volatile methyl formate. Reaction of fluorine-containing phenols with these dichloromethyl alkyl ethers did not give salicylaldehyde derivatives, leading instead to corresponding aryl formates in high yields. A plausible mechanism is discussed.
Novel method for synthesizing dolutegravir key intermediate 2,4-difluorobenzylamine
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Paragraph 0029; 0031; 0032; 0035, (2018/11/22)
The invention discloses a novel production method which is concise and green in route, low in cost and easy to industrialize to prepare 2,4-difluorobenzylamine. The method comprises the following twosteps: a) at certain pressure, carrying out a carbonylation reaction on m-difluorobenzene and CO in the presence of a catalyst so as to generate 2,4-difluorobenzaldehyde, or carrying out a formylationreaction on m-difluorobenzene, namely carrying out chlorocarbene substitution on m-difluorobenzene in a chloroform strong base system, and further carrying out hydrolysis so as to prepare a product 2,4-difluorobenzaldehyde (Reimer-Tiemann reactions); b) putting the product 2,4-difluorobenzaldehyde of the step a) into an alcohol solvent, at certain pressure, in the presence of the catalyst, carrying out a reduction ammonolysis reaction on the component with an ammonia gas and hydrogen directly in the presence of a catalyst, or enabling the component to react with ammonium formate, thereby obtaining the 2,4-difluorobenzylamine. The preparation method disclosed by the invention is simple and easy in raw material obtaining, concise in route, green and environmentally friendly, low in cost andeasy in industrial production.
Method for preparing 2,4-difluorobenzaldehyde through continuous oxidation of 2,4-difluorotoluene
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Paragraph 0040-0066, (2017/08/28)
The invention relates to a method for preparing 2,4-difluorobenzaldehyde through continuous oxidation of 2,4-difluorotoluene, and belongs to the technical field of organic synthesis processes. According to the method, a 2,4-difluorotoluene compound is adopted as a raw material, one or a plurality of metal ion complexes of cobalt, molybdenum and bromine are adopted as a catalyst, hydrogen peroxide is adopted as an oxidant, acetic acid is adopted as a solvent, and 2,4-difluorotoluene is continuously oxidized in a tubular reactor to prepare 2,4-difluorobenzaldehyde. According to the present invention, the method has advantages of mild condition, short reaction time, high raw material utilization rate, safety, stability, continuous operation and high production efficiency, and can achieve the effective control during the reaction process.
Aldehyde and Ketone Synthesis by P450-Catalyzed Oxidative Deamination of Alkyl Azides
Giovani, Simone,Alwaseem, Hanan,Fasan, Rudi
, p. 2609 - 2613 (2016/08/30)
Heme-containing proteins have recently attracted increasing attention for their ability to promote synthetically valuable transformations not found in nature. Following the recent discovery that engineered variants of myoglobin can catalyze the direct conversion of organic azides into aldehydes, we investigated the azide oxidative deamination reactivity of a variety of hemoproteins featuring different heme coordination environments. Our studies show that although several heme-containing enzymes possess basal activity in this reaction, an engineered variant of the bacterial cytochrome P450 CYP102A1 constitutes a particularly efficient biocatalyst for promoting this transformation, and it exhibits a broad substrate scope along with high catalytic activity (up to 11 300 turnovers), excellent chemoselectivity, and enhanced reactivity toward secondary alkyl azides to yield ketones. Mechanistic studies and Michaelis–Menten analyses provided insight into the mechanism of the reaction and the impact of active-site mutations on the catalytic properties of the P450. Altogether, these studies demonstrate that engineered P450 variants represent promising biocatalysts for the synthesis of aryl aldehydes and ketones through the oxidative deamination of alkyl azides under mild reaction conditions.
TRICYCLIC PIPERIDINE COMPOUNDS
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Page/Page column 111-112; 122, (2015/06/08)
The present invention relates to compounds of the formula (I), wherein R, R1a, R1b, R2, R3, and X are as described in the description, to their preparation, to pharmaceutically acceptable salts thereof, and to their use as pharmaceuticals, to pharmaceutical compositions containing one or more compounds of formula (I), to methods for the preparation of such compounds of formula (I), and especially to their use as TPH modulators.
Efficient conversion of primary azides to aldehydes catalyzed by active site variants of myoglobin
Giovani, Simone,Singh, Ritesh,Fasan, Rudi
, p. 234 - 239 (2015/12/30)
The oxidation of primary azides to aldehydes constitutes a convenient but underdeveloped transformation for which no efficient methods are available. Here, we demonstrate that engineered variants of the hemoprotein myoglobin can catalyze this transformation with high efficiency (up to 8500 turnovers) and selectivity across a range of structurally diverse aryl-substituted primary azides. Mutagenesis of the 'distal' histidine residue was particularly effective in enhancing the azide oxidation reactivity of myoglobin, enabling these reactions to proceed in good to excellent yields (37-89%) and to be carried out at a synthetically useful scale. Kinetic isotope effect, isotope labeling, and substrate binding experiments support a mechanism involving heme-catalyzed decomposition of the organic azide followed by alpha hydrogen deprotonation to generate an aldimine which, upon hydrolysis, releases the aldehyde product. This work provides the first example of a biocatalytic azide-to-aldehyde conversion and expands the range of non-native chemical transformations accessible through hemoprotein-mediated catalysis.
Practical Cu(OAc)2/TEMPO-catalyzed selective aerobic alcohol oxidation under ambient conditions in aqueous acetonitrile
Jiang, Jian-An,Du, Jia-Lei,Wang, Zhan-Guo,Zhang, Zhong-Nan,Xu, Xi,Zheng, Gan-Lin,Ji, Ya-Fei
supporting information, p. 1677 - 1681 (2014/03/21)
We reported a ligand-and additive-free Cu(OAc)2/TEMPO catalyst system that enables efficient and selective aerobic oxidation of a broad range of primary and secondary benzylic alcohols, primary and secondary 1-heteroaryl alcohols, cinnamyl alcohols, and aliphatic alcohols to the corresponding aldehydes and ketones. This ambient temperature oxidation protocol is of practical features like aqueous acetonitrile as solvent, ambient air as the terminal oxidant, and low catalyst loading, presenting a potential value in terms of both economical and environmental considerations. Based on the experimental observations, a plausible reaction mechanism was proposed.
