Synthesis of β- and γ-Carbolines by the Palladium/Copper-Catalyzed Coupling and Cyclization of Terminal Acetylenes Haiming Zhang Richard C. Larock 10.1021/jo0258857.s002 https://acs.figshare.com/articles/journal_contribution/Synthesis_of_-_and_-Carbolines_by_the_Palladium_Copper-Catalyzed_Coupling_and_Cyclization_of_Terminal_Acetylenes/3695355 A variety of 3-substituted β<i>-</i> and γ-carbolines have been synthesized from <i>N</i>-substituted 3-iodoindole-2-carboxaldehydes and 2-bromoindole-3-carboxaldehydes, respectively. The coupling of these aldehydes with various terminal acetylenes with PdCl<sub>2</sub>(PPh<sub>3</sub>)<sub>2</sub>/CuI as the catalyst readily affords the corresponding alkynylindole carboxaldehydes, which have subsequently been converted to the corresponding <i>tert</i>-butylimines and cyclized to β<i>-</i> and γ-carbolines by either copper-catalyzed or thermal processes. 2002-08-30 00:00:00 bromoindole Cyclization iodoindole PPh 3 variety Terminal Acetylenes Palladium CuI Synthesi PdCl 2 carboline alkynylindole carboxaldehydes Carboline butylimine cyclized tert terminal acetylenes catalyst