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A wide variety of regioselectively substituted carbazole derivatives can be synthesized by the gold‐catalyzed cyclization of alkynols bearing an indol‐3‐yl and an additional group at the homopropargylic positions. The regioselectivity of the process can be controlled by both the oxidation state of the gold catalyst and the electronic nature of the substituents of the alkynol moiety. The 1,2‐alkyl migration in the spiroindoleninium intermediate, generated after indole attack to the activated alkyne, is favored with gold(I) complexes and for electron‐rich aromatic substituents at the homopropargylic position, whereas the 1,2‐alkenyl shift is preferred when using gold(III) salts and for alkyl or non‐electron‐rich aromatic groups. [ABSTRACT FROM AUTHOR]

The combination of organolithium chemistry with gold catalysis has enabled the development of a synthetic strategy for accessing polysubstituted indoles and carbazoles from readily available starting materials. This method is based on a "back‐to‐front" approach from ketopyrroles, generated by intramolecular carbolithiation of N,N‐bis‐(2‐lithioallyl)amines that evolve into 3,4‐bis(lithiomethyl)dihydropyrrole intermediates capable of reacting with carboxylic esters and Weinreb amides. These ketopyrroles have demonstrated to be excellent precursors of mono or bis(alkynols)pyrroles that, under gold‐catalysis, experience a benzannulation reaction providing access to regioselectively substituted indoles or carbazoles. [ABSTRACT FROM AUTHOR]

Propargylic glycols, 2‐alkynyl‐1‐(indol‐3‐yl)‐1,2‐diols, react with thiols undergoing a complex but selective gold‐catalyzed transformation that gives rise to α‐indol‐3‐yl α‐((Z)‐2‐thioalkenyl) ketones. The sequence is triggered by the regioselective thiolation of indolyl diols followed by an attack of the sulfur instead of the indole over the activated alkyne. The final compounds are obtained in remarkably high yields and arise from simple starting materials such as indolyl acyloins, ethynyl magnesium bromide and thiols. [ABSTRACT FROM AUTHOR]