本文描述了一种空前的路易斯酸,其通过炔丙基炔醇与2-乙烯基苯酚的环加成反应,催化了有价值的3,4-二氢-2 H -2,4-甲烷二甲基苯并没有保护性地进行了高效合成。该环加成方案可耐受多种官能团,以令人满意的收率提供实用,通用且经济实惠的途径来获得新型的有吸引力的桥环产品。与报道的桥环骨架合成反应条件相比,目前的反应条件是中性,温和且没有任何添加剂。
Synthesis of 1,6-Dihydropyridine-3-carbonitrile Derivatives <i>via</i> Lewis Acid-Catalyzed Annulation of Propargylic Alcohols with (<i>E</i>)-3-Amino-3-phenylacrylonitriles
作者:Li-Juan Du、Yuecheng Zhang、Hong-Yu Zhang、Guohui Yin、Xiao-Yan Wang、Jiquan Zhao、Ya-Ping Han
DOI:10.1021/acs.joc.0c01171
日期:2020.8.7
acid-catalyzed, highly efficient, practical, and atom-economical protocol for the synthesis of functionalized 1,2-dihydropyridine-3-carbonitrile derivatives in the presence of Bi(OTf)3 (10 mol %) in tetrahydrofuran (2.0 mL) at 80 °C for 8 h in air is described, starting from readily accessed propargylic alcohols and (E)-3-amino-3-phenylacrylonitriles. This cycloaddition protocol, which is scalable and
A new method for the efficient synthesis of hexahydro-1H-fluorene and octahydrobenzo[a]azulene derivatives through a ring-expansion strategy is reported. With an appropriate combination of thulium(III) trifluoromethanesulfonate and 13X molecular sieves, a range of unsaturated polycycliccompounds were obtained in good yields. Mechanism studies reveal that the reaction is more likely to undergo Meyer–Schuster
An unprecedented Lewisacidcatalyzed [4 + 3] cycloaddition reaction is described that provides a straightforward route to polycyclic products containing an imine-based indole azepine scaffold, starting from readily available internal tertiary alkynols and azides. This cycloaddition protocol provides efficient and atom-economical access to a new class of fascinating imine-containing products in satisfactory
A novel highly efficient, environmentally benign Lewis acid‐catalyzed, and protection‐free protocol for the construction of valuable polycyclic products bearing a 1H‐pyrrolo[1,2‐a]indole scaffold is described, starting from readily available propargylic alcohols and 2‐ethynylanilines. The one‐pot transformation entails the cleavage of one C−O bond, and the construction of two C−N bonds and one C−C
描述了一种新型的高效,环境友好的路易斯酸催化且无保护的方案,用于构建带有1 H-吡咯并[1,2- a ]吲哚骨架的有价值的多环产物,从容易获得的炔丙醇和2开始乙炔基苯胺。一锅转换需要裂解一个C-O键,两个C-N键和一个C-C双键。这种独特的操作简单的方法是在温和条件下和空气中进行的,产生的水是唯一的副产物。它具有可伸缩性,并显示出良好的功能组兼容性和广泛的适用范围。
Lewis Acid‐Catalyzed Formal [3+3] Annulation of Propargylic Alcohols with 4‐Hydroxy‐2
<i>H</i>
‐chromen‐2‐ones
tricyclic compounds possessing functionalizedpyrano[3,2‐c]chromen‐5(2H)‐one fragments has been developed using propargylic alcohols and 4‐hydroxy‐2H‐chromen‐2‐ones as the substrates. The protocol provides a one‐step, environmentally benign method of accessing a broad range of pyrano[3,2‐c]chromen‐5(2H)‐one derivatives in excellent yields undermildconditions and with good functional‐group tolerance. The method