Electrophilic nitration of 2-trifluoromethylchromone and its 6- and 7-methoxy derivatives affords 6-, 5-, and 8-nitro derivatives, respectively, while 5,7-dimethyl-2-trifluoromethylchromone yields a 6,8-dinitro derivative. Radical chlorination results in 3-chloro derivatives.
One-pot synthesis of functionalized benzo[c]coumarins and their precursors via the reaction of 2-(polyfluoroalkyl)chromones with 4-alkyl-3-cyanocoumarins
作者:Vyacheslav Ya. Sosnovskikh、Vladislav Yu. Korotaev、Igor B. Kutyashev、Alexey Yu. Barkov、Alexander V. Safrygin
DOI:10.1039/c6ra12492e
日期:——
dichloromethane in the presence of triethylamine to give a wide variety of functionalized benzo[c]coumarin derivatives in good yields. This new annulation reaction presumably proceeds by a tandem intermolecular Michael addition and subsequent intramolecular condensationbetween an intermediate enolate anion and cyano group. In the case of 3-cyano-4-methylcoumarin and 2-(trifluoromethyl)chromones activated
2-(多氟烷基)色酮与4-烷基-3-氰基香豆素在二氯甲烷中,在三乙胺的存在下反应,以高收率得到各种官能化的苯并[ c ]香豆素衍生物。这种新的环化反应大概是通过串联分子间迈克尔加成反应以及随后的中间烯醇式阴离子和氰基之间的分子内缩合而进行的。在3-氰基-4-甲基香豆素和2-(三氟甲基)色酮被两个吸电子取代基激活的情况下,分离出三个无环中间体,并提出了可能的反应机理。
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作者:V. Ya. Sosnovskikh、B. I. Usachev
DOI:10.1023/a:1011357106750
日期:——
Morpholine adds smoothly at the double bond of substituted 5- and 8-nitro-2-trifluoromethylchromones to form the corresponding 2-morpholino-2-trifluoromethylchroman-4-ones. 6- Methoxy-5-nitro-2-trifluoromethylchromone adds also benzylamine, whereas 7-methoxy-8-nitro -2-trifluoromethylchromone undergoes ring opening under the action of benzylamine to give 3-benzylamino-4,4,4-trifluoro-1 -(2-hydroxy-4-methoxy-3-nitrophenyl)but-2-en-1 -one.
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作者:V. Ya. Sosnovskikh、B. I. Usachev
DOI:10.1023/a:1009544630187
日期:——
Electrophilic nitration of 2-trifluoromethylchromone and its 6- and 7-methoxy derivatives affords 6-, 5-, and 8-nitro derivatives, respectively, while 5,7-dimethyl-2-trifluoromethylchromone yields a 6,8-dinitro derivative. Radical chlorination results in 3-chloro derivatives.
One-Pot Domino Synthesis of Polyfunctionalized Benzophenones, Dihydroxanthones, and<i>m</i>-Terphenyls from 2-(Polyfluoroalkyl)chromones
作者:Vyacheslav Ya. Sosnovskikh、Vladislav Yu. Korotaev、Alexey Yu. Barkov、Igor B. Kutyashev、Alexander V. Safrygin
DOI:10.1002/ejoc.201403585
日期:2015.3
Whereas 2-(polyfluoroalkyl)chromones activated by electron-withdrawing substituents in the benzene ring react with 2-(1-phenylalkylidene)malononitriles in the presence of triethylamine in dichloromethane to produce a wide range of polyfunctionalizedbenzophenones and dihydroxanthones, their reactions with ethyl α-cyano-β-methylcinnamate under the same conditions took an entirely different course and