622-60-6Relevant articles and documents
Hydrosilylation of aromatic azomethines
Zuev,Kovaleva,Skvortsov
, p. 548 - 550 (2004)
The reactions of aromatic azomethines with methyldichlorosilane, phenyldichlorosilane, and dimethylchlorosilane, performed in the presence of Speier's, Wilkinson's, and Karstedt's catalysts and a series of Pt(II) complexes LL'PtCl2, give hydrosilylation and reduction products whose ratio depends on the catalyst used. The highest yield of hydrosilylation products is attained with Pt(II) complexes as catalysts.
A new alkylation of aryl alcohols by boron trifluoride etherate
Jumbam, Ndze Denis,Maganga, Yamkela,Masamba, Wayiza,Mbunye, Nomthandazo I.,Mgoqi, Esethu,Mtwa, Sphumusa
, (2019/10/28)
The ethylation of aryl alcohols by an ethyl moiety of boron trifluoride etherate is described. The reaction proceeded cleanly and afforded good yields of the corresponding aryl ethyl ethers. It tolerated the presence of functional groups such as aryl, alkyl, halogens, nitro, nitrile, and amino. However, the presence of amino or nitro groups ortho to a hydroxyl group of an aryl compound drastically reduced the yields of the anticipated products due to the chelation of the aforementioned functional groups with boron trifluoride etherate. A nitrogen atom in the aromatic ring system, as exemplified by hydroxypyridine and 8-hydroxyquinoline, completely inhibited the reaction. Resorcinol, hydroquinone, and aryl alcohols with aldehyde functions decomposed under the reaction conditions.
Transition-Metal-Free C-C, C-O, and C-N Cross-Couplings Enabled by Light
Liu, Wenbo,Li, Jianbin,Querard, Pierre,Li, Chao-Jun
, p. 6755 - 6764 (2019/05/06)
Transition-metal-catalyzed cross-couplings to construct C-C, C-O, and C-N bonds have revolutionized chemical science. Despite great achievements, these metal catalysts also raise certain issues including their high cost, requirement of specialized ligands, sensitivity to air and moisture, and so-called "transition-metal-residue issue". Complementary strategy, which does not rely on the well-established oxidative addition, transmetalation, and reductive elimination mechanistic paradigm, would potentially eliminate all of these metal-related issues. Herein, we show that aryl triflates can be coupled with potassium aryl trifluoroborates, aliphatic alcohols, and nitriles without the assistance of metal catalysts empowered by photoenergy. Control experiments reveal that among all common aryl electrophiles only aryl triflates are competent in these couplings whereas aryl iodides and bromides cannot serve as the coupling partners. DFT calculation reveals that once converted to the aryl radical cation, aryl triflate would be more favorable to ipso substitution. Fluorescence spectroscopy and cyclic voltammetry investigations suggest that the interaction between excited acetone and aryl triflate is essential to these couplings. The results in this report are anticipated to provide new opportunities to perform cross-couplings.
Synthetic method for dapagliflozin
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Paragraph 0015, (2018/03/26)
The invention relates to a synthetic method for dapagliflozin. The synthetic method is characterized in that 4-methylphenol is taken as a starting raw material, alkylation and bromination are performed, an alkylation reaction is performed with antisepsin, diazotization and chlorination are performed, and condensation, etherification and desmethoxy are performed with 2,3,4,6-tetrakis-O-trimethylsilyl-D-gluconolactone to obtain a hypoglycemic drug (dapagliflozin). The synthetic method has the following advantages: 4-methylphenol is taken as the starting raw material, and 4-methylphenol is low inprice and easily accessible than 5-bromo-2-chlorobenzoic acid; by adoption of the process, industrialization can be easily realized; in the synthesis process, raw materials which are highly toxic arenot used, so that dangerous processes are avoided; the synthesis path is short and novel, so that the operation is simple and convenient; and by adoption of the synthesis path, the purity of a finalproduct can be improved, and the purity can be 99% or above.
Preparation method of dapagliflozin intermediate
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Paragraph 0022; 0023; 0024; 0025, (2018/03/01)
The invention provides a preparation method of a dapagliflozin intermediate. The preparation method comprises the following steps: (1) by taking 4-methylphenol and bromoethane as raw materials, a polar solvent as a reaction solvent and an inorganic base as a catalyst, carrying out reaction for preparing 4-ethyoxyl methylbenzene; (2) by taking N-chlorosuccinimide and 4-ethyoxyl methylbenzene obtained in the step (1) as raw materials, a non-polar solvent as a reaction solvent and dibenzoyl peroxide as an initiator, carrying out reaction, thus obtaining 4-ethyoxyl benzyl chloride; (3) dissolving 4-ethyoxyl benzyl chloride obtained in the step (2) and 4-bromaniline into ethyl acetate, adding a catalyst lewis acid, and carrying out reaction, thus obtaining 5-bromo-2-amino-4-ethyoxyl diphenylmethane; and (4) carrying out diazotization reaction on 5-bromo-2-amino-4-ethyoxyl diphenylmethane obtained in the step (3), and then reacting with cuprous chloride, thus synthesizing 5-bromo-2-chloro-4'-ethyoxyl diphenylmethane. The preparation method provided by the invention has the advantages of low cost, low environmental stress and short synthetic route.
Practical Ligand-Free Copper-Catalysed Short-Chain Alkoxylation of Unactivated Aryl Bromides
Guo, Ying,Fan, Xue-Min,Nie, Min,Liu, Hong-Wei,Liao, Dao-Hua,Pan, Xian-Dao,Ji, Ya-Fei
, p. 4744 - 4755 (2015/08/03)
An efficient and practical short-chain alkoxylation of unactivated aryl bromides has been developed with special attention focussed on the applicability of the reaction. Sodium alkoxide is used as the nucleophile, and the corresponding alcohol as the solvent. The reaction requires neither precious metals nor organic ligands. It uses a catalytic system consisting of copper(I) bromide as a catalyst, the corresponding alkyl formate as a noncontaminating cocatalyst, and lithium chloride as an additive. A wide range of substrates and test cases highlight the synthetic utility of the approach. Considering the commercial accessibility and affordability of the feedstocks, this protocol shows promise as a new alternative for the sustainable preparation of aryl alkyl ethers.
SNAAP sulfonimidate alkylating agent for acids, alcohols, and phenols 1
Maricich, Tom J.,Allan, Matthew J.,Kislin, Brett S.,Chen, Andrea I-T.,Meng, Fan-Chun,Bradford, Christine,Kuan, Nai-Chia,Wood, Jeremy,Aisagbonhi, Omonigho,Poste, Alethea,Wride, Dustin,Kim, Sylvia,Santos, Therese,Fimbres, Michael,Choi, Dianne,Elia, Haydi,Kaladjian, Joseph,Abou-Zahr, Ali,Mejia, Arturo
, p. 3361 - 3368 (2014/01/06)
Stable, crystalline ethyl N-tert-butyl-4-nitrobenzenesulfonimidate has been prepared in high yield by direct O-ethylation of N-tert-butyl-4- nitrobenzenesulfonamide with iodoethane and silver(I) oxide in dichloromethane. This sulfonimidate directly ethylates various acids to esters; the stronger the acid, the faster it alkylates and in higher yield. It readily ethylates alcohols and phenols to ethers at room temperature in the presence of tetrafluoroboric acid catalyst without molecular rearrangements or racemization. We have defined these reactions as SNAAP alkylations: [substitution, nucleophilic of acids, alcohols and phenols]. The hard sulfonimidate alkylating agent is chemoselective, preferring oxygen > nitrogen > sulfur. The sulfonamide byproduct of alkylation is readily recycled to the sulfonimidate. Georg Thieme Verlag Stuttgart . New York.
Microwave-assisted alkylation of phenols by quaternary onium salts
Blint, Erika,Greiner, Istvan,Keglevich, Gyrgy
scheme or table, p. 22 - 27 (2012/04/10)
The alkylation of cresol and its analogues was accomplished by quaternary onium salts under solventless and microwave(MW) conditions using Cs 2CO3 as the base. The beneficial energy absorbing ability of the onium saltscould be clearly observed under MW conditions as compared to the thermal experiments and was relevant in the range of 110-125 °C.
Bis(μ-iodo)bis[(-)-sparteine]-dicopper: A versatile catalyst for direct O-Arylation and O-Alkylation of phenols and aliphatic alcohols with haloarenes
Satyanarayana, Ponnam,Maheswaran, Hariharasarma,Kantam, Mannepalli Lakshmi,Bhargava, Suresh
supporting information; experimental part, p. 788 - 790 (2011/08/22)
The easy to prepare dimeric bis(μ-iodo)bis[(-)-sparteine]- dicopper ([CuI{(-)-spa}]2 complex) is shown to be versatile catalyst for O-arylation and O-alkylation with various aryl halides with phenols and aliphatic alcohols respectively, including less reactive aryl chlorides, such as chlorobenzene under mild conditions.
Copper-catalyzed hydroxylation of aryl halides with tetrabutylammonium hydroxide: Synthesis of substituted phenols and alkyl aryl ethers
Paul, Rajesh,Ali, Md Ashif,Punniyamurthy, Tharmalingam
supporting information; experimental part, p. 4268 - 4272 (2011/02/25)
The selective hydroxylation of aryl iodides and aryl bromides with tetrabutylammonium hydroxide pentahydrate is described. For this, the combination of copper(I) iodide and 8-hydroxyquinaldine at 70-130C in a mixture of dimethyl sulfoxide and water (2:3) is used. The resultant phenols can be readily reacted with alkyl and allyl halides in situ to provide the corresponding alkyl or allyl aryl ethers in high yields. The reactions are simple, general, and efficient, affording substituted phenols and alkyl aryl ethers under aerobic conditions
