7469-77-4Relevant academic research and scientific papers
Selective Oxidation of 2-Methylnaphthalene to 2-Methyl-1-naphthol by Rhodococcus sp. M192
Taguchi, Hisataka,Kita, Shunbun,Kobayashi, Motoo,Tani, Yoshiki
, p. 769 - 772 (1996)
About 6000 isolates of microorganisms assimilating methylketones (C3-C6) were tested for their selective oxidation of 2-methylnaphthalene to 2-methyl-1-naphthol. Strain M192 was the highest 2-methyl-1-naphthol producer and was classified as the genus Rhodococcus. The optimal conditions for the site-specific oxidation were studied using resting Rhodococcus sp. M192. The 2-methyl-1-naphthol productivity was specifically increased using methylethylketone as a carbon source, 1-propanol as a solvent to dissolve the substrate, and ethylxanthate or diethyldithiocarbamate as an inhibitor of 2-naphthoic acid (side-product) production. In the presence of these compounds, 2-methylnaphthalene was specifically oxidized at the 1-position without the conversion to 2-naphthoic acid. The productivity of 2-methyl-1-naphthol was about 90 μM from 1 mM 2-methylnaphthalene.
Preparation method of menadione sodium hydrogen sulfite
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Paragraph 0058; 0072-0077, (2021/07/31)
The invention provides a preparation method of menadione sodium hydrogen sulfite. The preparation method comprises the following steps of: by taking alpha-methyl-gamma-butyrolactone and benzene as raw materials, preparing 2-methyl-3, 4-dihydro-1 (2H)-naphthalenone through Friedel-Crafts reaction; carrying out halogenation reaction on the 2-methyl-3, 4-dihydro-1 (2H)-naphthalenone and a halogenation reagent at the ortho position of carbonyl, and carrying out alkali elimination to prepare 2-methyl-1-naphthol; oxidizing the 2-methyl-1-naphthol through air to obtain 2-methyl-1, 4-naphthoquinone; and carrying out addition reaction on the 2-methyl-1, 4-naphthoquinone and sodium hydrogen sulfite to prepare the menadione sodium hydrogen sulfite. According to the method, the raw materials are cheap, easily available and low in cost; the process operation is safe, simple and convenient, less process wastewater is generated, and the method is green and environment-friendly; and the stability of the raw materials and intermediate products is high, high reaction activity and selectivity are high, reaction conditions are easy to realize, side reactions are few, the purity and yield of the product are high, and industrial production of the menadione sodium bisulfite can be facilitated.
Green preparation method of menadione sodium bisulfite
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Page/Page column 0070-0073, (2021/07/31)
The invention provides a preparation method of menadione sodium bisulfite. The method comprises the following steps of: by using cheap and easily available 3, 4-dihydro-1 (2H)-naphthalenone as a raw material, carrying out halogenation-elimination to obtain 1-naphthol; carrying out methylation reaction to generate 2-methyl-1-naphthol; carrying out air oxidation on the 2-methyl-1-naphthol to obtain 2-methyl-1, 4-naphthoquinone; and carrying out addition reaction on the 2-methyl-1, 4-naphthoquinone and sodium hydrogen sulfite so as to obtain the menadione sodium bisulfite. The method has the advantages of cheap and easily available raw materials, low cost, safe, simple and convenient process operation, less process wastewater generation, green and environment-friendly performance, high stability of raw materials and intermediate products, high reaction activity and selectivity, easy realization of reaction conditions, few side reactions and high product purity and yield, and can facilitate the industrial production of the menadione sodium bisulfite.
Controlling the Gold(I)-Catalyzed 1,5-Allenene Reaction: Construction of Fused Rings with Excellent Diastereoselectivity
Haberhauer, Gebhard,Semleit, Nina
supporting information, p. 9635 - 9639 (2021/12/06)
In the present study, the gold(I)-catalyzed reaction of 1,5-allenenes was controlled in such a way that instead of a [2 + 3] cycloaddition, a 5-exo-cyclization with the formation of a carbocation occurred. The latter could be trapped with both oxygen and carbon nucleophiles. In the investigated system, fused tricyclic frameworks with three contiguous stereocenters with excellent chemo- and diastereoselectivity in up to 95% yield were obtained.
Photocatalytic hydrogen evolution of 1-tetralones to α-naphthols by continuous-flow technology
He, Xu,Zheng, Yi-Wen,Lei, Tao,Liu, Wen-Qiang,Chen, Bin,Feng, Ke,Tung, Chen-Ho,Wu, Li-Zhu
, p. 3337 - 3341 (2019/07/10)
Taking advantage of the synergy between photocatalysis and cobaloxime catalysis, the keto-enol radical cation of 1-tetralones becomes compatible with the transformation of various 1-tetralones into α-naphthols and H2 by virtue of the continuous-flow approach without any sacrificial oxidants under unusually mild conditions.
Site-selective Oxidative Dearomatization of Phenols and Naphthols into ortho-Quinols or Epoxy ortho-Quinols using Oxone as the Source of Dimethyldioxirane
Cabrera-Afonso, María J.,Carre?o, M. Carmen,Urbano, Antonio
supporting information, (2019/08/21)
A novel reactivity of dimethyldioxirane, generated in situ from Oxone and acetone, with substituted phenols and naphthols is reported. This methodology allowed the synthesis of ortho-quinols or epoxy ortho-quinols from a site-selective oxidative dearomatization process, with good yields under very mild conditions. A short total synthesis of natural product lacinilene C methyl ether is also described using this process as the key step. (Figure presented.).
Formal Total Synthesis of Hybocarpone Enabled by Visible-Light-Promoted Benzannulation
Chen, Wei,Guo, Renyu,Yang, Zhen,Gong, Jianxian
, p. 15524 - 15532 (2019/01/03)
The formal total synthesis of hybocarpone was achieved in eight steps from commercially available 1,2,4-trimethoxybenzene. Key transformations include a visible-light-promoted benzannulation to construct the key α-naphthol intermediate and a modified CAN-mediated dimerization/hydration cascade sequence to generate the vicinal all-carbon quaternary centers in a stereocontrolled manner. The total synthesis of boryquinone was also achieved in seven steps.
Efficient cross-coupling of aryl/alkenyl triflates with acyclic secondary alkylboronic acids
Si, Tengda,Li, Bowen,Xiong, Wenrui,Xu, Bin,Tang, Wenjun
supporting information, p. 9903 - 9909 (2017/12/12)
Aryl-secondary alkyl cross-coupling with aryl sulfonate esters as coupling partners remains a significant challenge. Efficient cross-coupling between aryl/alkenyl triflates and acyclic secondary alkylboronic acids is realized for the first time to provide a series of sterically congested acyclic secondary alkyl arenes/olefins in good to excellent yields. The employment of sterically bulky P,PO ligand L1/L2 is crucial for the high yields and selectivities. The method has enabled a concise and 4-step synthesis of a key intermediate of male contraceptive agent and PAF antagonist gossypol.
Oxidative coupling of 1-naphthols over noble and base metal catalysts
Maphoru, Mabuatsela V.,Heveling, Josef,Pillai, Sreejarani K.
, p. 99 - 106 (2014/03/21)
Bismuth-promoted platinum catalysts were tested for the oxidative coupling of 2- and 4-substituted 1-naphthols at different temperatures and ambient pressure. The principal final products are the 3,3'-substituted 1,1'-binaphthalenylidene-4,4'- diones and the 4,4'-substituted 2,2'-binaphthalenylidene-1,1'- diones, respectively. Hydrogen peroxide was used as the oxidant. Only naphthols with electron-donating substituents reacted. The corresponding binaphthalenyl diols can be considered as reaction intermediates. Yields of up to 99% were obtained from 2-methyl-1-naphthol as the starting material within 20 minutes. Probably for steric reasons, the diol is the final product obtained from 2-ethyl-1-naphthol. For 4-methoxy- 1-naphthol the outcome is determined by the reaction temperature. At 25 8C the expected 1,1'-dione is the major product, whereas at 60 8C 1'-hydroxy-4'-methoxy-2,2'-binaphthalenyl- 1,4-dione is formed; the loss of one methoxy unit and the preservation of the hydroxy group can be explained by the competitive cleavage of one of the two O-Me bonds at higher temperature. Unpromoted platinum and a range of other metallic catalysts, including gold and Raney nickel, were also found to be active. The products obtained are brightly colored solids that could be used as dyes. The method described is truly catalytic and environmentally benign. The potential of the technique justifies further research to expand on the applicability of this novel method.
Substituent-induced regioselective hydroxylation of the aromatic C-H bond on naphthalene with metachloroperbenzoic acid catalyzed by F20TPPMnCl
Chen, Chang-Di,Sheng, Wen-Bing,Shi, Guo-Jun,Guo, Can-Cheng
, p. 23 - 29 (2013/03/13)
The regioselective hydroxylation of the aromatic C-H bond on a series of naphthalenes with different β-substituent R (R = H, Me, Et, i-Pr, OMe, COOH, Br, etc.) was studied, and the substituent effect on the regioselectivity was investigated. The electron-donating substituent afforded the aromatic C-H bond hydroxylation at the 1α position with more than 80% selectivity, while the electron-withdrawing substituent afforded the aromatic C-H bond hydroxylation at the 4α position with more than 60% selectivity of β-substituted naphthalene hydroxylated with metachloroperbenzoic acid catalyzed by tetrakis(pentafluorophenyl)porphyrin manganese(III) chloride. The research showed that the steric and electronic effects of the substituent appeared to play a significant role in determining the regioselectivity, and the electronic effect was of more importance than the steric effect of the substituent in the current situation. The studies may provide additional proofs for the stepwise mechanism of the aromatic C-H bond hydroxylation through a cationic intermediate. Copyright
