Ag(I)-Catalyzed Domino Cyclization-Addition Sequence with Simultaneous Carbonyl and Alkyne Activation as a Route to 2,2'-Disubstituted Bisindolylarylmethanes

Org Lett. 2016 Oct 21;18(20):5200-5203. doi: 10.1021/acs.orglett.6b02321. Epub 2016 Oct 6.

Abstract

An efficient synthesis of symmetrical 3, 3'-bisindolylarylmethanes with various substituents on the indole moiety has been developed by Ag(I)-catalyzed cycloisomerization and an deoxygenative addition sequence on o-alkynylanilines and aryl aldehydes. Ag(I) is proposed to activate alkyne unit and carbonyl moiety simultaneously leading to a domino first 5-endo-dig indole annulation, addition to C═O, second indole annulation, and its dehydroxylative addition.