- Phenol compound ortho-position direct fluorination method
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The invention relates to a phenol compound ortho-position direct fluorination method which comprises the following steps: reacting a phenol compound shown in a formula (1A) with a fluorination reagentin a solvent under the action of a photocatalyst and a light source at room temperature, and separating and purifying a reaction mixture after the reaction to obtain a fluorinated phenol compound shown in a formula (2A). The advantages are as follows: the method for directly fluorinating phenol by organic photocatalysis is simple in operation process; raw materials are commercialized and easy toobtain; the photocatalyst is low in price, easy to obtain and environmentally friendly; the reaction condition is mild; the site selectivity is high; the reaction is efficient; and a fluorinated phenol derivative can be prepared only through one step.
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Paragraph 0061-0063
(2020/04/17)
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- Ammonium Salt-Catalyzed Highly Practical Ortho-Selective Monohalogenation and Phenylselenation of Phenols: Scope and Applications
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An ortho-selective ammonium chloride salt-catalyzed direct C-H monohalogenation of phenols and 1,1′-bi-2-naphthol (BINOL) with 1,3-dichloro-5,5-dimethylhydantoin (DCDMH) as the chlorinating agent has been developed. The catalyst loading was low (down to 0.01 mol %) and the reaction conditions were very mild. A wide range of substrates including BINOLs were compatible with this catalytic protocol. Chlorinated BINOLs are useful synthons for the synthesis of a wide range of unsymmetrical 3-aryl BINOLs that are not easily accessible. In addition, the same catalytic system can facilitate the ortho-selective selenylation of phenols.
- Xiong, Xiaodong,Yeung, Ying-Yeung
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p. 4033 - 4043
(2018/05/22)
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- Synthesis of 2 - fluoro phenol compounds
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The present invention provides a method for synthetizing a 2-fluoro phenol compound shown in a formula IV. The phenol compound shown in the formula I is prepared into a 2-pyridine oxygroup arene compound shown in a formula II through an Ullmann reaction, the 2-pyridine oxygroup arene compound shown in the formula II is mixed with a palladium catalyst, a fluorinating reagent, an additive and an organic solvent, the mixture is stirred under the temperature of 30-160 DEG C to perform a fluorination reaction to obtain an ortho-position fluoridated 2-pyridine oxygroup arene compound shown in a formula III, and the ortho-position fluoridated 2-pyridine oxygroup arene compound shown in the formula III is prepared into the 2-fluoro phenol compound shown in the formula IV through the action of alkali. The method provided by the present invention has the advantages of mild reaction conditions, simplicity in operations, good substrate adaptability, high fluorination selectivity and the like. The 2-fluoro phenol compound is shown in the figure below.
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Paragraph 0054; 0055; 0058
(2017/04/21)
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- Arylsilane oxidation - New routes to hydroxylated aromatics
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An efficient route to hydroxylated aromatics has been developed, via the oxidation of aryl organosilanes under functional group-tolerant and relatively mild conditions, using sub-stoichiometric amounts of fluoride promoters.
- Bracegirdle, Sonia,Anderson, Edward A.
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supporting information; experimental part
p. 3454 - 3456
(2010/07/16)
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- The trifluoromethoxy group as a fluorine twin in the Diels-Alder reactions of halogenated quinones
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We describe here a study devoted to the comparison of the relative influence of chlorine, fluorine, and trifluoromethoxy substituents on the regiochemical outcome of the Diels-Alder reaction. For this purpose, we examined the behavior of mixed 'halogenated' quinones bearing these groups in their cycloadditions with simple dienes. Contrary to the expectation based on its known electronic properties, the trifluoromethoxy group behaves very much more like a fluorine than a chlorine atom in such reactions. On the basis on an endo transition state demonstrated here for these additions, we tentatively suggest that non-bonded interactions are the main factor controlling the regiochemistry.
- Magnier, Emmanuel,Diter, Patrick,Blazejewski, Jean-Claude
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p. 4575 - 4578
(2008/09/21)
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- Synthesis of halogenated phenols by directed ortho-lithiation and ipso-iododesilylation reactions of O-aryl N-isopropylcarbamates
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The regioselective synthesis of halogenated phenols via directed ortho-lithiation reactions of in situ N-silylated O-aryl N-isopropylcarbamates is reported. This protocol is complemented by ipso-iododesilylation reactions of C-silylated carbamates and iodine-magnesium exchange reactions, which are facilitated by the adjacent carbamoyl group. These methods provide an entry into a series of o-fluoro-, o-iodo-, and o,o′-diiodophenols in high yields which are otherwise difficult to obtain. Georg Thieme Verlag Stuttgart.
- Kauch, Matthias,Hoppe, Dieter
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p. 1578 - 1589
(2007/10/03)
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- Piperazine- and piperidine-derivatives as melanocortin receptor agonists
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The present invention relates to melanocortin receptor agonists of formula I, which is useful in the treatment of obesity, diabetes and male and/or female sexual dysfunction.
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Page/Page column 38
(2010/02/06)
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- Synthesis intermediates containing a hexane ring and processes for their preparation
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The present invention relates to new fluorinated hexane compounds corresponding to the following general formula (II): STR1 in which X'2, X'3 and X'4 are the same or different, and denote a halogen or a pseudohalogen, preferably a halogen, more preferably chlorine and fluorine, with the condition that, when R1 is hydroxyl, cyano, amido, imido, ethoxy, benzyloxy, cyclohexyloxy and tert-butoxy, not all the halogens can simultaneously be chlorine and R4, R3 and R5 are simultaneously equal to H; R1 denotes a hydrogen, a hydrocarbon chain such as an alkyl chain, alkoxy, cycloalkyl ether, an aromatic group, aromatic ether or an alkoxy, carbonyl, carboxyl or acyloxy, cyano, amido, imido or hydroxyl group; R4 denotes a hydrogen, a fluorine atom, a hydrocarbon chain such as, for example, an alkyl chain, an aromatic group or a carbonyl, carboxyl or carboxamide group or else a radical joined to the hexane ring by a chalcogen or by an element of Group V, preferably of the first Period, such as an amido, alkoxy or acyloxy group; in which the radicals R3 and R5, which are different or preferably the same, denote a fluorine, or preferably hydrogen, atom or also a hydrocarbon chain as defined above in the case of R4.
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