Lewis Acid-Catalyzed 1,4-Addition and Annulation of 4‑Hydroxy-coumarins with o‑Hydroxyphenyl Propargyl Amines: Entry to Regio-Selective Synthesis of Furano[3,2‑c]coumarins and Pyrano[3,2‑c]coumarins
A facile and regioselective Lewis acid-catalyzed cascade annulation of o-hydroxyphenyl propargyl amines with 4-hydroxycoumarin to afford furano[3,2-c]coumarin and pyrano[3,2-c]coumarin derivatives is reported. The reaction presumably proceeds by the conjugate addition of 4-hydroxycoumarin to the...
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Published in | Journal of organic chemistry Vol. 88; no. 7; pp. 4730 - 4742 |
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Main Authors | , |
Format | Journal Article |
Language | English |
Published |
WASHINGTON
American Chemical Society
07.04.2023
Amer Chemical Soc |
Subjects | |
Online Access | Get full text |
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Summary: | A facile and regioselective Lewis acid-catalyzed cascade annulation of o-hydroxyphenyl propargyl amines with 4-hydroxycoumarin to afford furano[3,2-c]coumarin and pyrano[3,2-c]coumarin derivatives is reported. The reaction presumably proceeds by the conjugate addition of 4-hydroxycoumarin to the in situ-generated alkynyl o-quinone methide and is followed by intramolecular 5-exo-dig and 6-endo-dig annulation to form furano[3,2-c]coumarins and pyrano[3,2-c]coumarins, respectively. The prepared o-hydroxyl substituted pyrano[3,2-c]coumarins could be readily transformed into the corresponding coumarin-derived dioxabicycles by acid-mediated cyclization. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0022-3263 1520-6904 |
DOI: | 10.1021/acs.joc.3c00213 |