Pd(II)-Catalyzed Fujiwara-Moritani Reactions for the Synthesis and Functionalization of Substituted Coumarins.
Ortiz de Elguea Flecha, Verónica
Carral Menoyo, Asier
Simón Vidal, Lorena
Martínez Nunes, Mikel
Barbolla Cuadrado, Iratxe
Lete, Marta G.
Sotomayor Anduiza, María Nuria
Lete Expósito, María Esther
ACS Omega 6(44) : 29483-29494 (2021)
[EN]Highly substituted coumarins, privileged and versatile scaffolds for bioactive natural products and fluorescence imaging, are obtained via a Pd(II)-catalyzed direct C–H alkenylation reaction (Fujiwara–Moritani reaction), which has emerged as a powerful tool for the construction and functionalization of heterocyclic compounds because of its chemical versatility and its environmental advantages. Thus, a selective 6-endo cyclization led to 4-substituted coumarins in moderate yields. Selected examples have been further functionalized in C3 through a second intermolecular C–H alkenylation reaction to give coumarin-acrylate hybrids, whose fluorescence spectra have been measured.