A high performance oxidation method for secondary alcohols by inductive activation of TEMPO in combination with pyridine–bromine complexes
摘要:
A new TEMPO-mediated catalytic oxidation method in combination with Py center dot HBr3 (stoichiometric) is developed for oxidation of secondary alcohols to the corresponding ketones. The performance of this oxidizing system is better compared with that of TEMPO method combined with R4NBr3 center dot Poly(4-vinylpyridine) HBr3 can be used in place of Py center dot HBr3. The electron-withdrawing substituent at the C-4 position of TEMPO increases the reactivity of TEMPO significantly in the oxidation of electron-deficient alcohols Such as polyhaloalkylmethanols. Inductive effect of the substituent of TEMPO is discussed through the characterization of the redox potential of N-O radical by cyclic voltammetry. (C) 2008 Elsevier Ltd. All rights reserved.
previously developed for the preparation of perfluoroalkyl sulfilimines by a reaction between fluorinated sulfoxides and nitriles, has been successfully extended to dinitriles. According to the reaction conditions, we can preferentially produce a cyano monosulfilimine or a bis(sulfilimine). New cyano thioethers have been synthesized through a rearrangement process. Mono- and bis(sulfilimine)s were also
Verfahren zur Herstellung von fluorierten Benzoesäuren
申请人:RIEDEL-DE HAEN AKTIENGESELLSCHAFT
公开号:EP0411252A1
公开(公告)日:1991-02-06
Bei dem Verfahren zur Herstellung von fluorierten Benzoesäuren der Formel I
worin X und Y z.B. unabhängig voneinander Chlor oder Fluor und X darüberhinaus auch Brom bedeuten, wird ein fluoriertes Chloracetophenon der Formel II
worin Z Chlor oder Wasserstoff bedeutet, mit einem Hypohalogenit umgesetzt.
在制备式 I 的氟化苯甲酸的过程中
式 II 的氟化氯代苯乙酮,其中 X 和 Y 分别是氯或氟,X 也是溴。
其中 Z 是氯或氢,与次卤酸反应。