Synthesis of trifluoromethyl-/cyclopropyl-substituted 2-isoxazolines by DBU-promoted domino reaction
作者:Xiao-Dong Liu、Hai-Yan Ma、Chun-Hui Xing、Long Lu
DOI:10.1016/j.cclet.2017.03.031
日期:2017.8
cyclopropyl substituted 2-isoxazolines were synthesized via a DBU-promoted domino reaction of β-trifluoromethyl-/β-cyclopropyl-substituted enones with hydroxylamine. The domino reaction consists of a Michael addition and the followed cyclization. A wide range of 3-substituted 5-cyclopropyl-5- trifluoromethyl-2-isoxazolines were obtained in good to excellent yields under mild reaction conditions. The method
Cuts both ways: The title reaction consists of an addition/cyclization/dehydration sequence and affords the biologically important chiral 3,5‐diaryl‐5‐(trifluoromethyl)‐2‐isoxazolines 1 in excellent yields with high ee values. The flexibility of accessing either the S or R enantiomers of the products has been achieved by the appropriate choice of phase‐transfer catalyst (2).
Benzylamine as Hydrogen Transfer Agent: Cobalt‐Catalyzed Chemoselective C=C Bond Reduction of β‐Trifluoromethylated α,β‐Unsaturated Ketones via 1,5‐Hydrogen Transfer
of β-CF3 -α,β-unsaturatedketones using benzylamine as hydrogen transfer agent involving intramolecular 1,5-hydrogen transfer is reported. The reaction proceeded smoothly with a relatively wide range of substrates including those bearing aromatic heterocycles such as a furyl ring system in high yields (74-92 %). This provides an efficient method for the synthesis of β-CF3 saturated ketones in one-pot
A Copper-Catalyzed Reductive Defluorination of β-Trifluoromethylated Enones via Oxidative Homocoupling of Grignard Reagents
作者:Xiaoting Wu、Fang Xie、Ilya D. Gridnev、Wanbin Zhang
DOI:10.1021/acs.orglett.8b00379
日期:2018.3.16
An efficient copper-catalyzed reductive defluorination of β-trifluoromethylated enones via an oxidative homocoupling of Grignard reagents is reported. The reaction proceeded smoothly with a wide range of substrates, including the ones bearing aromatic heterocycles, such as furyl and thienyl ring systems in high yields (80–92%, except one example) under mild conditions. This provides a practical method
An efficient one-pot method was developed for the construction of 3-acylindoles via oxidative rearrangement of 2-aminochalcones followed by intramolecular cyclization. The reaction was used to convert a variety of 2-aminochalcones into 3-acylindoles in moderate to high yields.