Copper-Mediated C–O/C–N Bond Formation: A Facile Synthesis of 3-Amidocoumarin, 3-Amidoazacoumarin, and N-Aroylindole ­Derivatives

Abstract

Three different heterocyclic systems, 3-amidocoumarins 1, 3-amidoazacoumarins 11, and N-benzoylindol-2-carboxamides 12 were synthesized based on the strikingly different selectivity of copper-mediated C-O/C-N bond formation from azlactones under conventional heating conditions. The results demonstrated that the stereochemistry of the double bond dictated the outcome of the products. The microwave irradiation played an important role in the isomerization of the trisubstituted olefin leading to the formation of 3-amidocoumarins 1 and 3-amidoazacoumarins 11. Compounds 1h, 1i, and 1l showed promising to good cytotoxic activity against a panel of cancer cell lines including HepG2 (hepatoblastoma) and MOLT-3 (T-lymphoblast acute lymphoblastic leukemia).

Base-Mediated and Silver-Catalyzed Divergent Synthesis of Hydroxynaphthalenamides and Phosphorylated Dihydronaphthylamides from Enone-Oxazolones

“…7 Recently, Muthukrishnan disclosed a transition-metal-free annulation reaction between benzynes and 1,3-oxopentanedioate to naphthalene derivatives (Scheme 1d). 8 From our previous work, azlactone analogs could be transformed to some highly functionalized molecules such as tricyclic imidazoloisoquinolin-3-ones, benzo[a]quinolizin-4ones, bicyclic 2, 3-dihydrobenzo[d]azocin-4-ones, 9 3-amidocoumarins, 3-amidoazacoumarins, 10 and phosphine-containing indane/indene derivatives. 11 To the best of our knowledge, there has been no reported synthetic approach to hydroxynaphthalenamides or dihydronaphthylamides employing azlactones as starting materials.…”