在室温下,用苯乙酮衍生物衍生的烯胺处理三氟乙醛乙基半缩醛,得到中间体的(E)-1,1,1,1-三氟-4-吗啉代-4-芳基-丁-3-烯-2-醇用于制备β-三氟甲基化的羟醛产物,4,4,4-三氟-3-羟基-1-芳基-丁丹-1-酮。中间体(E)-1,1,1-三氟-4-吗啉代-4-(4-硝基苯基)-丁-3-烯-2-醇的结构可以通过1 H,13 C NMR,IR鉴定和X射线晶体学。此外,中间体(E)-1,1,1,1-三氟-4-吗啉代-4-芳基-丁-3-烯-2-醇与氢在催化量(10 mol%)的钯/碳在三氟乙醇中的存在下于110℃平稳进行在室温下以良好至优异的产率得到1,1,1-三氟-4-芳基-2-丁醇。
N-sulfonylamidines. Part III. A new rearrangement reaction of N-alkylsulfonyl-amidines: Synthesis of enamines, β-aminosulfonyl-enamines and 4H-thiazete-S,S-dioxides.
作者:Francesca Clerici、Donato Pocar、Antonella Rozzi
DOI:10.1016/s0040-4020(01)96105-8
日期:1991.3
N-alkylsulfonylamidines (1) ( a newclass of amidines) rearrange by intramolecular attack of the carbanion generated α to the SO2 group on the amidine carbon. Through a cyclic thiazetidine intermediate three main classes of compounds are formed, i.e. enamines (), β-aminosulfonylenamines () and 4H-thiazete-S,S-dioxides (). In the rearrangement products and the two carbon moieties of the amidine formerly linked to
Enamine-assisted facile generation of trifluoroacetaldehyde from trifluoroacetaldehyde ethyl hemiacetal and its carbon–carbon bond forming reaction leading to β-hydroxy-β-trifluoromethyl ketones
Trifluoroacetaldehyde ethyl hemiacetal 1 readily reacts with various enamines 2 in hexane at room temperature for 1 h to give the corresponding β-hydroxy-β-trifluoromethyl ketones in good yields.
The Use of Trifluoroacetaldehyde Ethyl Hemiacetal or Hydrate in a Simple and Practical Regioselective Synthesis of β-Hydroxy-β-trifluoromethyl Ketones from Enamines and Imines
The reaction of trifluoroacetaldehyde ethyl hemiacetal or hydrate with an equimolar amount of enamines, derived from various methylketones, smoothly proceeded to give the corresponding beta-hydroxy-beta-trifluoromethyl ketones in high yields. An equimolar amount of imines derived from various methylketones with aliphatic, aromatic, and heteroaromatic substituents also readily reacted with trifluoroacetaldehyde