Regio- and Stereoselective Cross-Coupling of tert-Propargyl Alcohols with Bis(trimethylsilyl)acetylene and Its Utilization in Constructing a Fluorescent Donor−Acceptor System
摘要:
1,1-Disubstituted 3-aryl-2-propyn-1-ols undergo regio- and stereoselective cross-coupling on treatment with bis(trimethylsilyl)acetylene in the presence of a rhodium catalyst via cleavage of C(sp)-C(sp(3)) and C(sp)-Si bonds to produce the corresponding 2-hydroxymethyl-(E)-enynes. The subsequent desilylative Sonogashira coupling followed by base-promoted cyclization affords fluorescent dihydrofuran derivatives.
Zn(OTf)<sub>2</sub>-Catalyzed Formal [3 + 3] Cascade Annulation of Propargylic Alcohols with 2-Aminochromones: Accessing the Chromeno[2,3-<i>b</i>]pyridines
作者:Pei Tong、Zhou Sun、Shutao Wang、Yuan Zhang、Ying Li
DOI:10.1021/acs.joc.9b02120
日期:2019.11.1
A Zn(OTf)2-catalyzed formal [3 + 3] cascade annulation strategy for the synthesis of functionalized chromeno[2,3-b]pyridines has been developed using propargylicalcohols and 2-aminochromones as the substrates. The protocol provides a convenient and atom-economical method of accessing a broad range of chromeno[2,3-b]pyridine derivatives in excellent yields with good functional-group tolerance. The
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
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
A novel copper(II) trifluoromethanesulfonate‐catalyzed intermolecular cascade annulation strategy for the construction of a great variety of pentacyclic compounds possessing valuable carbazole fragments was developed employing propargylic alcohols and (Z)‐2‐styryl‐1H‐indoles as the initial substrates. This protocol, which entails a sequential Meyer‐Schuster rearrangement/isomerization/‐cyclization