81842-71-9Relevant articles and documents
Nickel-catalyzed reductive monofluoroakylation of alkyl tosylate with bromofluoromethane to primary alkyl fluoride
Cui, Ru,Hu, Duo-Duo,Sheng, Jie,Wang, Xi-Sheng,Wu, Bing-Bing,Zheng, Hong-Qian
supporting information, p. 9084 - 9087 (2021/09/14)
A nickel-catalysed direct terminal monofluoromethlyation between alkyl tosylates and a low-cost, industrial raw material bromofluoromethane has been developed. This transformation has demonstrated high efficiency, mild conditions, and good functional-grou
Erbium-Catalyzed Regioselective Isomerization-Cobalt-Catalyzed Transfer Hydrogenation Sequence for the Synthesis of Anti-Markovnikov Alcohols from Epoxides under Mild Conditions
Liu, Xin,Longwitz, Lars,Spiegelberg, Brian,T?njes, Jan,Beweries, Torsten,Werner, Thomas
, p. 13659 - 13667 (2020/11/30)
Herein, we report an efficient isomerization-transfer hydrogenation reaction sequence based on a cobalt pincer catalyst (1 mol %), which allows the synthesis of a series of anti-Markovnikov alcohols from terminal and internal epoxides under mild reaction conditions (≤55 °C, 8 h) at low catalyst loading. The reaction proceeds by Lewis acid (3 mol % Er(OTf)3)-catalyzed epoxide isomerization and subsequent cobalt-catalyzed transfer hydrogenation using ammonia borane as the hydrogen source. The general applicability of this methodology is highlighted by the synthesis of 43 alcohols from epoxides. A variety of terminal (23 examples) and 1,2-disubstituted internal epoxides (14 examples) bearing different functional groups are converted to the desired anti-Markovnikov alcohols in excellent selectivity and yields of up to 98%. For selected examples, it is shown that the reaction can be performed on a preparative scale up to 50 mmol. Notably, the isomerization step proceeds via the most stable carbocation. Thus, the regiochemistry is controlled by stereoelectronic effects. As a result, in some cases, rearrangement of the carbon framework is observed when tri-and tetra-substituted epoxides (6 examples) are converted. A variety of functional groups are tolerated under the reaction conditions even though aldehydes and ketones are also reduced to the respective alcohols under the reaction conditions. Mechanistic studies and control experiments were used to investigate the role of the Lewis acid in the reaction. Besides acting as the catalyst for the epoxide isomerization, the Lewis acid was found to facilitate the dehydrogenation of the hydrogen donor, which enhances the rate of the transfer hydrogenation step. These experiments additionally indicate the direct transfer of hydrogen from the amine borane in the reduction step.
The synthesis of precursor of FP- (+) DTBZ
Wu, Caijiao,Li, Hui,Sun, Feiyang,Bao, Changshun,Bao, Xuefei,Chen, Guoliang
, p. 3218 - 3225 (2019/09/13)
A synthetic route to the precursor of FP- (+) DTBZ was disclosed, in which 3-hydroxy-4-methoxybenzaldehyde was employed as a starting material. In the method, the benzyl-protecting protocol and the in-situ Diels-Alder reaction made the procedure more practical because of the mild conditions for selectively deprotection and the accelerated reaction process.
