Coupling and Cyclization of o-Iodoanilines and Propargylic Bromides via Allenes: An Efficient Entry to Indomethacin

A sequential allene synthesis and cyclization has been realized in a one-pot manner. A Pd(0)-catalyzed one-pot reaction of N-Ts or -Ms 2-iodoanilines and propargylic bromides afforded indoles with pharmaceutical importance highly efficiently with diversity via sequential carbon carbon bond coupling forming allenes and azapalladation. With this newly established methodology, an efficient approach to indomethacin, an anti-inflammatory drug (NSAID), has been accomplished.