Diversity-Oriented Synthesis of Benzo[<i>f</i>][1,4]oxazepine-, 2<i>H</i>-Chromene-, and 1,2-Dihydroquinoline-Fused Polycyclic Nitrogen Heterocycles under Microwave-Assisted Conditions
作者:Diksha Rajput、Dolma Tsering、Muthu Karuppasamy、Kamal K. Kapoor、Subbiah Nagarajan、C. Uma Maheswari、Nattamai Bhuvanesh、Vellaisamy Sridharan
DOI:10.1021/acs.joc.3c00552
日期:2023.7.7
An efficient, diversity-oriented synthesis of oxazepino[5,4-b]quinazolin-9-ones, 6H-chromeno[4,3-b]quinolines, and dibenzo[b,h][1,6]naphthyridines was established involving a substrate-based approach under microwave-assisted and conventional heating conditions in high yields (up to 88%). The CuBr2-catalyzed, chemoselective cascade annulation of O-propargylated 2-hydroxybenzaldehydes and 2-aminobenzamides
建立了氧氮杂[5,4- b ]喹唑啉-9-酮、6 H-色并[4,3- b ]喹啉和二苯并[ b , h ][1,6]萘啶的高效、多样性合成涉及在微波辅助和传统加热条件下基于基材的方法,产率高(高达 88%)。CuBr 2催化的O-炔丙基化 2-羟基苯甲醛和 2-氨基苯甲酰胺的化学选择性级联成环作用传递了 oxazepino[5,4- b ]quinazolin-9-ones,涉及 6- exo - trig环化-空气氧化-1,3-质子位移-7- exo-dig环化序列。这种一锅法表现出优异的原子经济性(−H 2 O),并在一次合成操作中构建了两个新的杂环(六元和七元)和三个新的C-N键。另一方面,O / N-炔丙基化2-羟基/氨基苯甲醛和2-氨基苯甲醇之间的反应产生6 H-色并[4,3- b ]喹啉和二苯并[ b,h][1,6]萘啶涉及顺序亚胺形成-[4 + 2]杂-狄尔斯-阿尔德反应