α-Dimethylaminomethylenation-induced Houben–Hoesch-type cyclization of cyanoacetanilides: a practical synthesis of 3-formyl-4-hydroxyquinolin-2(1H)-ones
摘要:
The tandem reaction of cyanoacetanilides with triflic anhydride in DMF proceeded at room temperature to afford 3-formyl-4-hydroxyquinolin-2(1H)-ones in good to high yields. A detailed mechanistic study revealed that the tandem reaction proceeded via alpha-dimethylaminomethylenation, which promoted the subsequent Houben-Hoesch-type cyclization. Both alpha-functionalization and the cyclization steps were optimized, and a multi-gram scale synthesis of 3-formyl-4-hydroxyquinolin-2(1H)-one was achieved. (C) 2011 Elsevier Ltd. All rights reserved.
A Concise and Versatile Synthesis of Viridicatin Alkaloids from Cyanoacetanilides
摘要:
The efficient synthesis of 3-hydroxy-4-arylquinolin-2(1H)-ones through one-pot Knoevenagel condensation/epoxidation of cyanoacetanilides followed by decyanative epoxide-arene cyclization is described. A convergent assembly with functionalized aldehydes allows for rapid synthesis with diverse substitution patterns. Isolation of 3-hydroxy-4-arylquinolin-2(1H)-ones is readily accomplished by precipitation and filtration.
α-Dimethylaminomethylenation-induced Houben–Hoesch-type cyclization of cyanoacetanilides: a practical synthesis of 3-formyl-4-hydroxyquinolin-2(1H)-ones
The tandem reaction of cyanoacetanilides with triflic anhydride in DMF proceeded at room temperature to afford 3-formyl-4-hydroxyquinolin-2(1H)-ones in good to high yields. A detailed mechanistic study revealed that the tandem reaction proceeded via alpha-dimethylaminomethylenation, which promoted the subsequent Houben-Hoesch-type cyclization. Both alpha-functionalization and the cyclization steps were optimized, and a multi-gram scale synthesis of 3-formyl-4-hydroxyquinolin-2(1H)-one was achieved. (C) 2011 Elsevier Ltd. All rights reserved.
A Concise and Versatile Synthesis of Viridicatin Alkaloids from Cyanoacetanilides
作者:Yusuke Kobayashi、Takashi Harayama
DOI:10.1021/ol900255g
日期:2009.4.2
The efficient synthesis of 3-hydroxy-4-arylquinolin-2(1H)-ones through one-pot Knoevenagel condensation/epoxidation of cyanoacetanilides followed by decyanative epoxide-arene cyclization is described. A convergent assembly with functionalized aldehydes allows for rapid synthesis with diverse substitution patterns. Isolation of 3-hydroxy-4-arylquinolin-2(1H)-ones is readily accomplished by precipitation and filtration.