| Popis: |
An efficient annulation strategy involving the reaction of phenolic acetates with acrylates in the presence of [Rh2(OAc)4] as catalyst and formic acid as reducing agent, leading to the high yield synthesis of coumarin derivatives, has been developed. The addition of NaOAc as a base increased the yield of the products. The reaction is quite successful for both electron-rich as well as electron-deficient phenolic acetates, affording coumarins with excellent regioselectivity, and proceeds via C–H bond activation proven by deuterium incorporation studies. |
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