Synthesis of C3-functionalized indole derivatives via Brønsted acid-catalyzed regioselective arylation of 2-indolylmethanols with guaiazulene

A Bronsted acid catalyzed method for the construction of guaiazulenyl C3-functionalized indole derivatives is reported for the first time. The reactions proceeded smoothly at ambient temperature by using (+/-)-10-camphorsulfonic acid (CSA) as a catalyst, 2-indolylmethanols and guaiazulene as substrates, and the desired products were obtained in high yields with excellent regioselectivities.