A general synthesis of alkenyl-substituted benzofurans, indoles, and isoquinolones by cascade palladium-catalyzed heterocyclization/oxidative Heck coupling.
Structurally diverse C3-alkenylbenzofurans, C3-alkenylindoles, and C4-alkenylisoquinolones are efficiently prepared by using consecutive Sonogashira and cascade Pd-catalyzed heterocyclization/oxidative Heck couplings from readily available ortho-iodosubstituted phenol, aniline, and benzamide substrates, alkynes, and functionalized olefins. The cyclization of O- and N-heteronucleophiles follows regioselective 5-endo-dig- or 6-endo-dig-cyclization modes, whereas the subsequent Heck-type coupling with both mono- and disubstituted olefins takes place stereoselectively with exclusive formation of the E isomers in most cases.
Alvarez
Rosana
R
Departamento de Química Orgánica, Facultad de Química, Universidade de Vigo, Lagoas Marcosende, 36310 Vigo, Spain. rar@uvigo.es
Martínez
Claudio
C
Madich
Youssef
Y
Denis
J Gabriel
JG
Aurrecoechea
José M
JM
de Lera
Angel R
AR