Gold(III)-catalyzed cycloisomerization of α-bis(indol-3-yl)methyl alkynols selectively affords 1-(indol-3-yl)carbazoles, in a transformation that takes place through a selective 1,2-alkyl vs 1,2-vinyl migration step in the vinyl-gold intermediate generated from the initial 5-endo-spirocyclization. The reaction proceeds well with either tertiary or secondary starting alkynols as well as with a wide variety of alkyne substituents. The key role of the other indol-3-yl substituent for the unexpected selectivity in the 1,2 rearrangement has also been supported by DFT calculations that reveal a low barrier, two-step mechanism in the alkyl migration path where the second indole significantly stabilizes a carbocationic intermediate.

A straightforward and efficient synthesis of the two less explored types of indolocarbazoles has been developed giving rise to highly fluorescent compounds with fluorescence quantum yields around 0.7.

Abstract. Described is a general and efficient synthesis of valuable benzo [b]carbazoles by Brønsted acid-catalyzed reaction between simple C2,C3-unsubstituted indoles and o-(-(hydroxy)benzyl)benzaldehyde acetals. Highly selective migration processes are involved as key steps in the overall cascade sequence that implies the one-pot formation of two new bonds and a cycle in a regioselective fashion.

Abstract. An efficient methodology for the synthesis of a series of new fused polyclyclic indoles has been developed by Brønsted acid-catalyzed intramolecular FriedelCrafts reactions of properly designed indolyl alcohols.

This work describes the 6- endo - dig cyclization of S -aryl propargyl sulfides to afford 2 H -thiochromenes. The substitution at the propargylic position plays a crucial role in allowing intramolecular silver-catalyzed alkyne hydroarylation and N -iodosuccinimide-promoted iodoarylation. Additionally, a PTSA-catalyzed thiolation reaction of propargylic alcohols was developed to synthesize the required tertiary S -aryl propargyl ethers. The applicability of merging these two methods is demonstrated by synthesizing the retinoic acid receptor antagonist AGN194310.

A convenient procedure for accessing α,α‐bis(indol‐3‐yl) ketones from indoles and α‐oxoaldehydes is described using an inexpensive and commercially available catalyst such as p‐toluenesulfonic acid monohydrate. This protocol allows for the first time the synthesis of 2,2‐bis(indolyl)‐1‐alkylethanones by employing aliphatic 2‐oxoaldehydes, even as aqueous solutions. The high‐yielded obtained ketones have been shown as useful starting materials for further synthetic transformations.

A new and efficient synthesis of α-functionalized α-indol-3-yl ketones from easily available indolyl α-acyloins is reported. This process, catalyzed by Brønsted or Lewis acids, involves an uncommon direct nucleophilic substitution reaction of a secondary α-carbonyl-substituted hydroxyl group. The described methodology allows the introduction of a variety of nucleophiles such as (hetero)arenes, thiophenols, nitroanilines and 1,3-dicarbonyl derivatives. The synthesized α-indol-3-yl carbonyl compounds are important synthetic targets also useful for accessing functionalized tryptophols and furan-3-yl indoles.

No abstract