A new access to benzofulvenes bearing an indol-3-yl substituent at C-2 has been developed. Treatment of 3-propargylindoles possessing an additional hydroxy group at the other propargylic position with a cationic gold(I) complex triggers a tandem 1,2-indole migration/aura-iso-Nazarov cyclization/elimination sequence that takes place under mild conditions.
作者:Estela Álvarez、Olalla Nieto Faza、Carlos Silva López、Manuel A. Fernández-Rodríguez、Roberto Sanz
DOI:10.1002/chem.201502174
日期:2015.9.7
A cascadereaction of indoles with propargylic diols involving an unprecedented metal‐free 1,2‐indole migration onto an alkyne was carried out. DFT calculations support a mechanism consisting of a concerted nucleophilic attack of the indole nucleus with loss of water, followed by the 1,2‐migration and subsequent Nazarov cyclization. This Brønsted acid‐catalyzed protocol affords indole‐functionalized