99-93-4Relevant academic research and scientific papers
Synthesis method of p-hydroxyacetophenone
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Paragraph 0030-0039, (2021/08/06)
The invention relates to the technical field of fine chemical synthesis, in particular to a synthesis method of p-hydroxyacetophenone. The synthesis method comprises the following steps of: mixing anisole and o-dichlorobenzene, then adding zinc oxide, then adding aluminum trichloride under a cooling condition, finally dropwise adding acetyl chloride, heating and stirring for reaction, cooling after reaction is finished, pouring reaction liquid into ice water for extraction and extinguishment, carrying out reduced pressure distillation to recover o-dichlorobenzene, then cooling and crystallizing, and then filtering and drying to obtain the p-hydroxyacetophenone. Under the joint promotion action of zinc oxide and aluminum trichloride, the two-step reaction of acetylation and demethylation can be continuously carried out after one-time feeding, and a real one-step synthetic reaction is realized in a one-pot way, so that the operation process is simplified, and the problems of more by-products, low yield and the like caused by inactivation of aluminum trichloride due to repeated feeding are reduced.
Rapid, chemoselective and mild oxidation protocol for alcohols and ethers with recyclable N-chloro-N-(phenylsulfonyl)benzenesulfonamide
Badani, Purav,Chaturbhuj, Ganesh,Ganwir, Prerna,Misal, Balu,Palav, Amey
supporting information, (2021/06/03)
Chlorine is the 20th most abundant element on the earth compared to bromine, iodine, and fluorine, a sulfonimide reagent, N-chloro-N-(phenylsulfonyl)benzenesulfonamide (NCBSI) was identified as a mild and selective oxidant. Without activation, the reagent was proved to oxidize primary and secondary alcohols as well as their symmetrical and mixed ethers to corresponding aldehydes and ketones. With recoverable PS-TEMPO catalyst, selective oxidation over chlorination of primary and secondary alcohols and their ethers with electron-donating substituents was achieved. The reagent precursor of NCBSI was recovered quantitatively and can be reused for synthesizing NCBSI.
Chemoselective and ligand-free aerobic oxidation of benzylic alcohols to carbonyl compounds using alumina-supported mesoporous nickel nanoparticle as an efficient recyclable heterogeneous catalyst
Das, Asit Kumar,Nandy, Sneha,Bhar, Sanjay
, (2021/05/10)
An economically efficient and operationally simple ligand-free protocol for the chemoselective oxidation of benzylic alcohols to carbonyl compounds has been developed using alumina-supported nickel nanoparticles as a stable recyclable heterogeneous catalyst along with potassium tert-butoxide in the presence of aerial oxygen as an eco-friendly oxidant. The aliphatic alcohols remained unaffected under the present condition. Excellent chemoselectivity has also been demonstrated through intermolecular and intramolecular competition experiments. This protocol accommodates a diverse range of substituents with the tolerance of various sensitive moieties during the reaction. The catalyst could be recovered by filtration and reused consecutively without any significant loss in the catalytic activity. Moreover, the heterogeneity of the catalyst has also been established by the “hot filtration method (Sheldon's test)”.
Radical-anion coupling through reagent design: hydroxylation of aryl halides
Chechik, Victor,Greener, Andrew J.,James, Michael J.,Oca?a, Ivan,Owens-Ward, Will,Smith, George,Ubysz, Patrycja,Whitwood, Adrian C.
, p. 14641 - 14646 (2021/11/17)
The design and development of an oxime-based hydroxylation reagent, which can chemoselectively convert aryl halides (X = F, Cl, Br, I) into phenols under operationally simple, transition-metal-free conditions is described. Key to the success of this approach was the identification of a reducing oxime anion which can interact and couple with open-shell aryl radicals. Experimental and computational studies support the proposed radical-nucleophilic substitution chain mechanism.
Decarboxylative Hydroxylation of Benzoic Acids
Ritter, Tobias,Su, Wanqi,Xu, Peng
supporting information, p. 24012 - 24017 (2021/10/06)
Herein, we report the first decarboxylative hydroxylation to synthesize phenols from benzoic acids at 35 °C via photoinduced ligand-to-metal charge transfer (LMCT)-enabled radical decarboxylative carbometalation. The aromatic decarboxylative hydroxylation is synthetically promising due to its mild conditions, broad substrate scope, and late-stage applications.
Photocatalytic Reductive C-O Bond Cleavage of Alkyl Aryl Ethers by Using Carbazole Catalysts with Cesium Carbonate
Yabuta, Tatsushi,Hayashi, Masahiko,Matsubara, Ryosuke
, p. 2545 - 2555 (2021/02/01)
Methods to activate the relatively stable ether C-O bonds and convert them to other functional groups are desirable. One-electron reduction of ethers is a potentially promising route to cleave the C-O bond. However, owing to the highly negative redox potential of alkyl aryl ethers (Ered -2.6 V vs SCE), this mode of ether C-O bond activation is challenging. Herein, we report the visible-light-induced photocatalytic cleavage of the alkyl aryl ether C-O bond using a carbazole-based organic photocatalyst (PC). Both benzylic and non-benzylic aryl ethers underwent C-O bond cleavage to form the corresponding phenol products. Addition of Cs2CO3 was beneficial, especially in reactions using a N-H carbazole PC. The reaction was proposed to occur via single-electron transfer (SET) from the excited-state carbazole to the substrate ether. Interaction of the N-H carbazole PC with Cs2CO3 via hydrogen bonding exists, which enables a deprotonation-assisted electron-transfer mechanism to operate. In addition, the Lewis acidic Cs cation interacts with the substrate alkyl aryl ether to activate it as an electron acceptor. The high reducing ability of the carbazole combined with the beneficial effects of Cs2CO3 made this otherwise formidable SET event possible.
Development of pH-activatable fluorescent probes for rapid visualization of metastatic tumours and fluorescence-guided surgeryviatopical spraying
Cao, Wenwen,Li, Xiaoxin,Wu, Peng,Xiong, Hu
supporting information, p. 10636 - 10639 (2021/10/19)
A series of pH-activatable aza-BODIPY-based fluorescent probes were developed for rapid cancer visualization and real-time fluorescence-guided surgery by harnessing topical spraying. These probes exhibited good water-solubility, a tunable pKafrom 5.0 to 7.9, and stable intense NIR emission at ～725 nm under acidic conditions.AzaB5with a pKavalue of 6.7 was able to rapidly and clearly visualize pulmonary and abdominal metastatic tumours including tiny metastases less than 2 mmviatopical spraying, further improving intraoperative fluorescence-guided resection. We believe thatAzaB5is promising as a powerful tool to rapidly delineate a broad range of malignancies and assist surgical tumour resection.
Aryl phenol compound as well as synthesis method and application thereof
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Paragraph 0237-0240, (2021/05/12)
The invention discloses a synthesis method of an aryl phenol compound shown as a formula (3). All systems are carried out in an air or nitrogen atmosphere, and visible light is utilized to excite a photosensitizer for catalyzation. In a reaction solvent, ArNR1R2 as shown in a formula (1) and water as shown in a formula (2) are used as reaction raw materials and react under the auxiliary action of acid to obtain the aryl phenol compound as shown in a formula (3). The ArNR1R2 in the formula (1) can be primary amine and tertiary amine, can also be steroid and amino acid derivatives, and can also be drugs or derivatives of propofol, paracetamol, ibuprofen, oxaprozin, indomethacin and the like. The synthesis method has the advantages of cheap and easily available raw materials, simple reaction operation, mild reaction conditions, high reaction yield and good compatibility of substrate functional groups. The fluid reaction not only can realize amplification of basic chemicals, but also can realize amplification of fine chemicals, such as synthesis of drugs propofol and paracetamol. The invention has wide application prospect and use value.
Catalyst-free rapid conversion of arylboronic acids to phenols under green condition
Dong, Zhenhua,Liu, Mengmeng,Pan, Hongguo
, (2021/09/06)
A catalyst-free and solvent-free method for the oxidative hydroxylation of aryl boronic acids to corresponding phenols with hydrogen peroxide as the oxidizing agent was developed. The reactions could be performed under green condition at room temperature within very short reaction time. 99% yield of phenol could be achieved in only 1 min. A series of different arenes substituted aryl boronic acids were further carried out in the hydroxylation reaction with excellent yield. It was worth nothing that the reaction could completed within 1 min in all cases in the presence of ethanol as co-solvent.
