Br?nsted acidic ionic liquid-promoted direct C3-acylation of N-unsubstituted indoles with acid anhydrides under microwave irradiation

摘要

A green and efficient pathway for the synthesis of 3-acylindoles using a Br?nsted acidic ionic liquid as a catalyst has been developed for the first time. The C3-acylation of N-unsubstituted indoles with acid anhydrides affords the desired products in good to excellent yields with high regioselectivity under microwave irradiation. Moreover, the Br?nsted acidic ionic liquid can be recycled up to four times without significant loss of catalytic activity.