| Abstract
| - Various kinds of 6H-dibenzo[b,d]pyran-6-ones 4 were synthesized via a sequential one-pot procedureusing the Sonogashira coupling−benzannulation reaction of aryl 3-bromopropenoates 1, in whichthe ortho-position of aryl group is substituted with enynes or iodine, with acetylenes 2 in the presenceof palladium and copper catalysts. The Sonogashira coupling between the aryl 3-bromopropenoates1a and 1b, bearing enynes at the ortho-position of aryl group, and alkynes 2a−g gave the enyneintermediates 3 in situ, which subsequently underwent the palladium-catalyzed benzannulationreaction to afford the 6H-dibenzo[b,d]pyran-6-ones 5a−g and 6. The Sonogashira coupling betweenthe aryl 3-bromopropenoate 1c, bearing iodine at the ortho-position of aryl group, and diynes 2fand 2h produced the diyne intermediates 13, which underwent the benzannulation reaction toafford the 6H-dibenzo[b,d]pyran-6-ones 14f and 14h.
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