triazolochromenes were formed with complete regioselectivity and new biologically relevant structures were synthesized via extension of the developed procedure and via postfunctionalization. The mechanochemical synthesis was carried out for several salicylaldehydes and gave a clear improvement in the yield of the corresponding triazolochromenes and consequently showed to be a viable alternative for solid salicylaldehydes
Facile access to 2-aryl-3-nitro-2H-chromenes and 2,3,4-trisubstituted chromanes
作者:Ping-An Wang、Dong-Xu Zhang、Xue-Ying Liu
DOI:10.3998/ark.5550190.p008.801
日期:——
materials, 2-aryl-3-nitro-2H-chromenes were prepared in good yields (up to 83%) through the combination of 30 mol% of pyrrolidine- benzoic acid catalyzed tandem oxa-Michael-Henry reactions in refluxing ethanol. Additionally, the Michael reactions of 2-aryl-3-nitro-2H-chromenes with acetone were also performed by the same catalytic combination in brine to give 2,3,4-trisubstitutedchromanes up to 86%
Molecular diversity of the domino annulation reaction of 2-aryl-3-nitrochromenes with pivaloylacetonitriles
作者:Wang Jiang、Jing Sun、Ru-Zhang Liu、Chao-Guo Yan
DOI:10.1039/c8ob01504j
日期:——
In the presence of triethylamine, the domino annulation reaction of two molecules of pivaloylacetonitrile with one molecule of 2-aryl-3-nitrochromene in tetrahydrofuran resulted in the unprecedented imino-substituted dihydrofuro[2,3-c]chromene derivatives in high yields.
KO<i>t</i>Bu-Mediated Aza-Michael Addition of Aromatic Amines or<i>N</i>-Phenylurea to 3-Nitro-2-phenyl-2<i>H</i>-chromenes and Sequential Aerobic Dehydrogenation
作者:Meshari A Alsharif、Danish Khan、Sayeed Mukhtar、Mohammed Issa Alahmdi、Naseem Ahmed
DOI:10.1002/ejoc.201800431
日期:2018.7.13
An efficient KOtBu‐mediated aza‐Michaeladdition of aromatic amines and/or N‐phenylurea derivatives to 3‐nitro‐2‐phenyl‐2H‐chromenes followed by aerobic dehydrogenation is reported. A wide range of 4‐(phenylamino)‐3‐nitro‐2‐phenyl‐2H‐chromene derivatives were synthesized in good‐to‐high yields (68–86 %) at 35–40 °C within 5–10 minutes under cost‐effective and operationally convenient conditions.
据报道,在3-硝基-2-苯基-2- H 2-苯并二氢苯并呋喃中进行了有效的KO t Bu介导的氮杂苯胺和/或N-苯基脲衍生物的氮杂-迈克尔加成反应,然后进行好氧脱氢。在35–40°C下,于5–10分钟内,在40–86%的条件下以高至高收率(68–86%)合成了各种4-(苯氨基)-3-硝基-2-苯基-2- H -2具有成本效益和操作方便的条件。
“On-Water”-Promoted<i>C</i>-Alkylation of Indoles with 2-Aryl-3-nitro-2<i>H</i>-chromenes under Catalyst-Free Conditions
作者:Pateliya Mujjamil Habib、Veerababurao Kavala、B. Rama Raju、Chun-Wei Kuo、Wen-Chang Huang、Ching-Fa Yao
DOI:10.1002/ejoc.200900207
日期:2009.9
An environmentally benign method for the synthesis of indolyl(nitro)chromans from indoles and 2-aryl-3-nitro-2Hchromenes undercatalyst-freeconditions by use of an “onwater” concept is described. The salient features of the methodology are its clean reaction conditions, the eco-friendly