Regio- and stereoselective synthesis of 1-benzopyrano[2,3-b]pyrrolo[2,3-d]pyridines: A microwave-accelerated intramolecular [3+2] cycloaddition reaction of azomethine ylide
作者:Sourav Maiti、T. M. Lakshmykanth、Suman Kalyan Panja、Ranjan Mukhopadhyay、Ayan Datta、Chandrakanta Bandyopadhyay
DOI:10.1002/jhet.567
日期:2011.7
Regio‐ and stereoselective syntheses of tetracyclic compounds having chromone, pyrrolidine, and piperidine rings have been accomplished by an intramolecular [3+2] cycloadditionreaction involving azomethineylide. The reactions were carried out thermally as well as by irradiation with microwave. The latter process accelerates the reaction. The selectivities were investigated by density functional theory
2-(N-Alkenyl-N-aryl)aminochromone-3-carbaldehyde undergoes intramolecular Povarov reaction with aromatic amines in the presence of Ph3P·HClO4 to produce chromenonaphthyridine. The effects of substituent and catalyst have been studied. The substituent on the alkenyl part of aminochromone controls the mode of reaction as well as the stereochemistry of the product.
The reaction of 2-(N-alkenyl-N-aryl)amino-4-oxo-4H-1-benzopyran-3-carbaldehyde with dimedone/Meldrum’s acid/4-hydroxycoumarin by heating in ethanol in the presence of pyridine produces polycyclicheterocycles bearing pyridine and pyran rings in a one-pot reaction. The effect of substituents on N-atom of the amino function controls the mode of reaction. Terminal alkenes prefer intramolecular Michael
通过在吡啶存在下于乙醇中加热,使2-(N-烯基-N-芳基)氨基-4-氧代-4 H -1-苯并吡喃-3-甲醛与二甲酮/麦德鲁姆酸/ 4-羟基香豆素反应生成多环一锅反应中带有吡啶和吡喃环的杂环。取代基对氨基官能团的N-原子的影响控制了反应方式。末端烯烃偏爱分子内迈克尔型反应,但非末端烯烃偏爱Diels-Alder反应,而在类似条件下,2-(N-烷基-N-烯丙基)氨基-4-氧代-4 H -1-苯并吡喃-3 -甲醛经历多米诺-Knoevenagel-杂Diels-Alder反应。