52134-15-3Relevant academic research and scientific papers
Use of the 2-Pyridinesulfonyloxy Leaving Group for the Fast Copper-Catalyzed Coupling Reaction at Secondary Alkyl Carbons with Grignard Reagents
Shinohara, Riku,Morita, Masao,Ogawa, Narihito,Kobayashi, Yuichi
, p. 3247 - 3251 (2019)
Investigation of the copper-catalyzed coupling reaction of 2-pyridinesulfonates with Grignard reagents revealed that reactions with catalytic Cu(OTf)2 were completed in 40 min. The results differed from those of the previous CuI-catalyzed reactions of tosylates in the presence of additives (LiOMe and TMEDA) for 12-24 h. It was shown that the preferred coordination of the leaving group to the reagents accelerated the reaction. Successful reagents were MeMgCl and other RMgX. Complete inversion was established.
Preparation method of labetalol hydrochloride
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Paragraph 0084; 0086-0087, (2021/11/27)
The invention provides a preparation method of labetalol hydrochloride, and belongs to the technical field of medicines. The invention provides a preparation method. The method comprises the following steps: carrying out nucleophilic substitution reaction on 5-halogenated acetyl salicylamide serving as an initial raw material and benzylamine, and then carrying out nucleophilic substitution reaction on the obtained product and 3-halogenated butylbenzene (or carrying out amine-ester exchange reaction on the obtained product and an esterification reaction product of 3-hydroxybutylbenzene and p-toluenesulfonyl chloride); and carrying out catalytic hydrogenation reaction and salifying to obtain the labeolol hydrochloride. According to the preparation method provided by the invention, benzylamine is adopted to replace dibenzylamine, so that the raw materials are high in atom utilization rate and environment-friendly, and atom economy of green chemistry is embodied; wherein the amine-ester exchange reaction is high in selectivity, and the obtained product is directly used for the next-step reaction. The one-step method is adopted to remove the protective agent and reduce carbonyl, so that the process route is shortened; meanwhile, the preparation method is simple and convenient to operate, high in stability and controllability, high in production cost, high in yield and suitable for industrial production.
Deoxyfluorination with CuF2: Enabled by Using a Lewis Base Activating Group
Bode, Bela E.,Chabbra, Sonia,Champion, Sue,Dawson, Daniel M.,Sood, D. Eilidh,Sutherland, Andrew,Watson, Allan J. B.
supporting information, p. 8460 - 8463 (2020/04/10)
Deoxyfluorination is a primary method for the formation of C?F bonds. Bespoke reagents are commonly used because of issues associated with the low reactivity of metal fluorides. Reported here is the development of a simple strategy for deoxyfluorination, using first-row transition-metal fluorides, and it overcomes these limitations. Using CuF2 as an exemplar, activation of an O-alkylisourea adduct, formed in situ, allows effective nucleophilic fluoride transfer to a range of primary and secondary alcohols. Spectroscopic investigations have been used to probe the origin of the enhanced reactivity of CuF2. The utility of the process in enabling 18F-radiolabeling is also presented.
Cobalt-Catalyzed Silylcarbonylation of Unactivated Secondary Alkyl Tosylates at Low Pressure
Roque Pena, Joan E.,Alexanian, Erik J.
supporting information, p. 4413 - 4415 (2017/09/11)
A catalytic preparation of silyl enol ethers from unactivated secondary alkyl tosylates is reported. An inexpensive cobalt catalyst is used under mild conditions with low pressures of carbon monoxide. Nucleophilic, anionic cobalt carbonyls facilitate the catalytic activation of a range of alkyl tosylates. The silylcarbonylation offers a practical approach to synthetically valuable silyl enol ethers from simple starting materials.
A simple route to 1,4-addition reactions by Co-catalyzed reductive coupling of organic tosylates and triflates with activated alkenes
Hsieh, Jen-Chieh,Chu, Yi-Hua,Muralirajan, Krishnamoorthy,Cheng, Chien-Hong
supporting information, p. 11584 - 11587 (2017/10/27)
An efficient Co-catalyzed 1,4-addition reaction of alkyl/aryl triflates and tosylates with activated alkenes is described. In this reaction, an air-stable cobalt(ii) complex, a mild reducing agent Zn and a simple proton source (H2O) are used. A radical mechanism for the addition of alkyl tosylates to activated alkenes is likely involved.
Copper-Catalyzed Reductive Cross-Coupling of Nonactivated Alkyl Tosylates and Mesylates with Alkyl and Aryl Bromides
Liu, Jing-Hui,Yang, Chu-Ting,Lu, Xiao-Yu,Zhang, Zhen-Qi,Xu, Ling,Cui, Mian,Lu, Xi,Xiao, Bin,Fu, Yao,Liu, Lei
supporting information, p. 15334 - 15338 (2016/02/18)
A copper-catalyzed reductive cross-coupling reaction of nonactivated alkyl tosylates and mesylates with alkyl and aryl bromides was developed. It provides a practical method for efficient and cost-effective construction of aryl-alkyl and alkyl-alkyl C=C bonds with stereocontrol from readily available substrates. When used in an intramolecular fashion, the reaction enables convenient access to various substituted carbo- or heterocycles, such as 2,3-dihydrobenzofuran and benzochromene derivatives.
