DABCO-Promoted three-component regioselective synthesis of functionalized chromen-5-ones and pyrano[3,2-c]chromen-5-ones via direct annulation of α-oxoketene-N,S-arylaminoacetals under solvent-free conditions
作者:Maya Shankar Singh、Ganesh Chandra Nandi、Subhasis Samai
DOI:10.1039/c1gc16129f
日期:——
hitherto unreported 3-aroyl-4-aryl-2-arylamino-4H-pyrano[3,2-c]chromen-5-ones has been developed by an one-pot three-component domino coupling of α-oxoketene-N,S-arylaminoacetals, aromatic aldehydes, and dimedone/4-hydroxycoumarin in the presence of DABCO under solvent-free conditions in high yields. Further, suitably substituted pyrano[3,2-c]chromen-5-ones undergo intramolecular aromatic nucleophilic
一种有效且收敛的方法,可制得3-芳基-4-芳基-2-芳基氨基-4,6,7,8-四氢铬基-5-酮和迄今未报道的3-芳基-4-芳基-2-芳基氨基-4 H-吡喃基[3,2 - c ] chromen-5-ones通过α-氧杂环丁烯-N,S-芳基氨基缩醛,芳族化合物的一锅三组分多米诺偶联而开发。醛类,和二甲酮/4-羟基香豆素 在......的存在下 达博在无溶剂条件下高收率。此外,适当取代的吡喃并[3,2- c ] chromen-5-ones会经历分子内芳族亲核取代(小号Ñ氩)以优异的收率得到五环吡喃并[3,2- c ]苯并喹啉。这种级联的优点Knoevenagel缩合/迈克尔加法/环化该序列具有高原子经济性,高收率,在一次操作中产生三个新键(两个C–C和一个C–O)的效率以及一个立体中心的特点。该协议避免了使用昂贵的催化剂,有毒有机试剂/溶剂和无水条件。特别地,该方法的吸引人的特征是在相似的反