Synthesis of fluoren-9-ones by the palladium-catalyzed cyclocarbonylation of o-halobiaryls.
The synthesis of various substituted fluoren-9-ones has been accomplished by the palladium-catalyzed cyclocarbonylation of o-halobiaryls. The cyclocarbonylation of 4'-substituted 2-iodobiphenyls produces very high yields of 2-substituted fluoren-9-ones bearing either electron-donating or electron-withdrawing substituents. 3'-Substituted 2-iodobiphenyls afford 3-substituted fluoren-9-ones in excellent yields with good regioselectivity. This chemistry has been successfully extended to polycyclic fluorenones and fluorenones containing fused isoquinoline, indole, pyrrole, thiophene, benzothiophene, and benzofuran rings.
Campo
Marino A
MA
Department of Chemistry, Iowa State University, Ames, Iowa 50011, USA.
Larock
Richard C
RC