Microwave-induced domino-Knoevenagel-hetero Diels–Alder reaction—an easy route to di[1]benzopyrano[2,3-b:4′,3′-d]pyridine
摘要:
MW-irradiation of a well-ground equimolar mixture of 2-(N-allcynyl-N-aryl)aminochromone-3-carbaldehyde and dimedone underwent domino-Knoevenagel-hetero Diels-Alder (DKHDA) reaction for nonterminal alkynes, whereas conventional heating of the above reaction mixture in ethanol in the presence of pyridine accomplished alkyne-carbonyl metathesis (ACM) reaction or both ACM and DKHDA reaction. Here is the first example of an organo-catalyzed ACM reaction. (C) 2014 Elsevier Ltd. All rights reserved.
Iodine/CuI-mediated alkyne–carbonyl metathesis reaction: synthesis of 1-aryl-1,2-dihydrochromeno[2,3-b]azepine-3,6-dione
摘要:
Iodine/cuprous iodide-mediated intramolecular alkyne carbonyl metathesis reaction has been developed using 2,-(N-aryl-N-propargyl)aminochromone-3-carbaldehyde as the substrate. It led to the synthesis of hitherto unreported chromeno[2,3-b]azepine-3,6-dione. The special features of this methodology are mild reaction conditions, 100% atom economy and use of inexpensive reagents. This is the first example of I-2/Cul-mediated alkyne carbonyl metathesis reaction. (C) 2013 Elsevier Ltd. All rights reserved.