一锅合成官能化苯并[ C ^ ]香豆素和它们的前体经由2-(多氟烷基)色酮与4-烷基-3- cyanocoumarins反应†
摘要:
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。
The nitration of 6,8-dibromo-2-trifluoromethylchromone depends on the reaction conditions and affords 6,8-dibromo-5-nitro- or 3,6,8-tribromo-5-nitro-2-trifluoromethylchromones. The structures of these compounds were determined from the H-1 and C-13 NMR spectroscopic data.
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