tert-BuOK-mediated carbanion–yne intramolecular cyclization: synthesis of 2-substituted 3-benzylbenzofurans
摘要:
A mild, efficient, and regioselective carbanion-yne intramolecular cyclization mediated by t-BuOK for the synthesis of 2-substituted 3-benzylbenzofurans is developed. It was started from o-iodophenol (1), based on O-alkylation, and the Sonogashira reaction in sequence to produce 2-(2-phenylethynyl-phenoxy)-1-arylalkanones (5). An intramolecular carbanion-yne 5-exo-dig cyclization reaction of 5, which was mediated by t-BuOK, yielded title benzofurans in good yields. (C) 2011 Elsevier Ltd. All rights reserved.
A highly efficient ultrasound-promoted synthesis of 2,3-disubstituted benzo[b]furans via intramolecular C–C bond formation in ionic liquid[bmim]BF<sub>4</sub>at room temperature
作者:Nisha Yadav、Mohd. Kamil Hussain、Mohd. Imran Ansari、Puneet K. Gupta、Kanchan Hajela
DOI:10.1039/c2ra22355d
日期:——
An efficient ultrasound-promoted synthesis of 2,3-disubstitutedbenzo[b]furans in the ionic liquid [bmim]BF4 at room temperature is reported. 5-exo-dig carbanion–yne intramolecularcyclization is mediated using anhydrous K3PO4 as a mild, inexpensive base under atmospheric conditions giving the title benzo[b]furans in excellent yields. Ionic liquid [bmim]BF4 has been used both as a reaction medium,
据报道,在室温下,在离子液体[bmim] BF 4中超声有效地促进了2,3-二取代的苯并[ b ]呋喃的合成。在大气条件下,使用无水K 3 PO 4作为温和且廉价的碱,可以介导5 -exo-dig Carbanion-yne分子内环化反应,从而以优异的收率得到标题为benzo [ b ]呋喃的化合物。离子液体[bmim] BF 4既用作反应介质,又用作形成CC键的催化剂。
Intermolecular Sonogashira Coupling and Intramolecular 5-<i>Exo</i>-<i>dig</i> Cycloisomerization Cascade: A One-Pot Pathway for Accessing (3-Benzylbenzofuran-2-yl)(phenyl)methanones
作者:Dakoju Ravi Kishore、Gedu Satyanarayana
DOI:10.1021/acs.joc.2c01101
日期:2022.8.5
straightforward strategy enabling access to 2,3-disubstitutedbenzo[b]furans. The whole synthetic process proceeds via a domino intermolecular Sonogashira coupling of 2-(2-bromophenoxy)-1-phenylethan-1-ones/alkyl 2-(2-bromophenoxy)acetates/2-(2-bromophenoxy)acetonitrile/1-(2-bromophenoxy)propan-2-one with terminal acetylenes followed by an intramolecular carbanion-yne cyclization in a 5-exo-dig manner and subsequent