我们发现,在位置2处带有2-卤代芳基取代基的菲并[9,10- d ]咪唑经历了快速的光化学驱动直接芳基化反应,从而导致鲜为人知的菲并[9',10':4,5]咪唑[1,2- f ]菲啶。该反应是高产率的,并且不需要任何敏化剂或碱。所发现的过程可耐受位置1和2上都存在的各种取代基;即,允许强供电子和吸电子取代基以及各种杂环单元。立体障碍不影响该过程。这里收集的证据表明S RN在这种情况下,一种机制正在起作用,其中自由基阴离子的形成是关键步骤,然后是碳-卤素键的杂合裂解。还显示了TfO基团进行环化,这允许在杂环体系的构建中使用水杨醛。通过分别具有13个和17个共轭环的两个系统的合成,已经证明了这种光化学驱动的直接芳基化的效率。苯并[9',10':4,5]咪唑并[1,2- f ]菲啶是蓝色发射体,与前体形成鲜明对比的是,它们在溶液和固态下均显示出强荧光。
aerobic oxidative synthesis of 2-arylbenzo[d]oxazoles, 2-substituted benzo[d]thiazoles, and 1,2-disubstituted benzo[d]imidazoles. N-Heterocyclic carbene (NHC), generated in situ from easily available N-heterocyclic imidazolium salt with air as terminal oxidant, has successfully been utilized as a cheap and efficient catalyst for one-pot aerobic oxidative synthesis of 2-arylbenzo[d]oxazoles, 2-substituted
摘要 N-杂环卡宾(NHC)是由易获得的N-杂环咪唑盐以空气为末端氧化剂原位生成的,已成功地用作便宜且有效的一锅好氧氧化合成2-芳基苯并[ d ]恶唑的催化剂,2-取代的苯并[ d ]噻唑和1,2-二取代的苯并[ d ]咪唑。 N-杂环卡宾(NHC)是由易获得的N-杂环咪唑盐以空气为末端氧化剂原位生成的,已成功地用作便宜且有效的一锅好氧氧化合成2-芳基苯并[ d ]恶唑的催化剂,2-取代的苯并[ d ]噻唑和1,2-二取代的苯并[ d ]咪唑。
Conventional and Microwave-Assisted Synthesis of Benzimidazole Derivatives and Their<i>In Vitro</i>Inhibition of Human Cyclooxygenase
作者:Daniela Secci、Adriana Bolasco、Melissa D'Ascenzio、Flavio della Sala、Matilde Yáñez、Simone Carradori
DOI:10.1002/jhet.1058
日期:2012.9
A large series of 1,2‐diaryl‐benzimidazole and 2‐aryl‐1H‐benzimidazolederivatives were synthesized with slight differences using both microwave irradiation and conventional heating methods. Usually higher yields and time reactions reduction were obtained with the former method. All compounds were assayed for their in vitro ability to inhibit humancyclooxygenases, and most of them showed an encouraging
Decarboxylative Cross-Coupling of Mesylates Catalyzed by Copper/Palladium Systems with Customized Imidazolyl Phosphine Ligands
作者:Bingrui Song、Thomas Knauber、Lukas J. Gooßen
DOI:10.1002/anie.201208025
日期:2013.3.4
The activation of the inert CO bonds in mesylates through the use of a new class of imidazolyl phosphines allows the decarboxylative coupling of aryl mesylates as well as polysubstituted alkenyl mesylates. Variation of the ligands leads to two complementary methods providing the corresponding biaryls and polysubstituted olefins in good yields.