The site selective synthesis of functionalized indoles is presented under environmentally convenient tetrabutylammonium fluoride catalysis. The metal-free approach exploits the combined efficiency of Bu4N+ and F− ions in performing a cascade sequence involving intramolecular hydroamination of the C–C triple bond, cleavage of silyl-protecting groups and site-selective sigmatropic aza-Cope-type [3,3]-rearrangement. A range of C(3)-allenyl-(1H)-indoles (2) is obtained in an efficient manner (yield up to 93%) providing a valuable synthetic alternative to noble metal-based protocols.
A., D.N., S., S., M., F., M., M., M., B. (2017). TBAF catalyzed one-pot synthesis of allenyl-indoles. ORGANIC CHEMISTRY FRONTIERS, 4, 1849-1853 [10.1039/c7qo00414a].
TBAF catalyzed one-pot synthesis of allenyl-indoles
DE NISI, ASSUNTA;FERRARA, MARCELLO;MONARI, MAGDA;BANDINI, MARCO
2017
Abstract
The site selective synthesis of functionalized indoles is presented under environmentally convenient tetrabutylammonium fluoride catalysis. The metal-free approach exploits the combined efficiency of Bu4N+ and F− ions in performing a cascade sequence involving intramolecular hydroamination of the C–C triple bond, cleavage of silyl-protecting groups and site-selective sigmatropic aza-Cope-type [3,3]-rearrangement. A range of C(3)-allenyl-(1H)-indoles (2) is obtained in an efficient manner (yield up to 93%) providing a valuable synthetic alternative to noble metal-based protocols.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
