An efficient and highlyselective approach for the synthesis of functionalized 4H-chromenes has been developed via gold(III)-catalyzed condensation/annulation tandem reaction of ketones with phenols.
Cyclopropanation of areno-condensed 4H-pyrans with dihalocarbenes
作者:Irina А. Semenova、Vitaly А. Osyanin、Maxim R. Demidov、Dmitry V. Osipov、Yuri N. Klimochkin
DOI:10.1007/s10593-020-02831-0
日期:2020.11
The addition of dihalocarbenes to 1H-benzo[f]chromenes and 4H-chromenes gave a number of dihalotetrahydro(benzo)cyclopropa[b]-chromenes containing donor and acceptor substituents at different positions. It was found that in the case of 1,3-disubstituted 1H-benzo[f]-chromenes, the reaction proceeds diastereoselectively with the formation of trans-isomers. 12H,13H-7a,12a-Methanobenzo[f]indeno-[1,2-b]chromene
向1 H-苯并[ f ]色烯和4 H-色烯中添加二卤卡宾,得到许多在不同位置含有供体和受体取代基的二卤四氢(苯并)环丙烷[ b ]-色烯。发现在1,3-二取代的1 H-苯并[ f ]-色烯的情况下,该反应非对映选择性地进行,形成反式异构体。12 H,13 H -7a,12a-甲基苯并[ f ]茚满-[1,2- b ]色烯和12,13-二氢-14 H -7a,13a-甲基二苯并[ a,h获得了新杂环系统代表的吨蒽。
Ultrasound-assisted one-pot synthesis of disubstituted and trisubstituted 1H-benzo[f]chromene derivatives catalyzed by 4-nitro-2,6-diacetylpyridinebis(2,4,6-trimethylaniline)FeCl2
作者:Reza Sandaroos、Saman Damavandi
DOI:10.1007/s11164-012-0933-y
日期:2013.11
1,3-Diaryl-1H-benzo[f]chromenes and 1,3-diaryl-1H-benzo[f]chromen-2-yl)(phenyl)methanones have been synthesized by one-pot three-component reaction of naphthols, aromatic aldehydes, and acetophenone or 1,3-diphenylpropane-1,3-dione, with the bis(imino)pyridine iron-based catalyst 4-nitro-2,6-diacetylpyridinebis(2,4,6-trimethylaniline)FeCl2. This novel, efficient, and rapid method is performed under solvent-free conditions with ultrasonic irradiation.