An efficient conversion of 4-bromo-3-yn-1-ols to γ-butyrolactones via AuCl(3)-catalyzed electrophilic cyclization (hydroxyl-assisted regioselective hydration) in wet toluene is described. Various secondary and tertiary alcohols including benzylic systems were found to be equally reactive with moderate to excellent yields obtained in all cases.

We describe herein a silver-catalyzed conversion of 1-(2-aminophenyl)-propargyl alcohols to 4-substituted 3-tosylaminoquinolines using TsN3 as an amino surrogate. Controlled reactions reveal the pathway consisting of Ag(I)-catalyzed 5-exo-dig cyclization, catalyst-free (2 + 3) cycloaddition, and ring-expansive rearrangement via nitrogen expulsion. As a support study, we show that the cyclic enamines in similar conditions produce amidines via a C-C bond migration.

A general method for isoxazoles from readily available ynones using trimethylsilyl azide as an amino surrogate, likely via an unprecedented hydroazidation of the alkyne and denitrogenative cyclization, is demonstrated. The method neither required any catalyst nor demanded unusual conditions to afford the products with outstanding functional group compatibility.

A method to prepare 3‐substituted‐2‐formylindole derivatives from N‐Boc‐ortho‐aminoaryl ketones and ethoxyacetylene through a cascade of reactions in a single operation that included a nucleophile‐triggered 5‐exo‐dig cyclization and an acid‐mediated 1,3‐allyl alcohol isomerization (1,3‐AAI) is described. A variety of aryl, vinyl and alkynyl groups can be introduced at C‐3 of indole‐2‐carboxaldehyde while having a high functional group compatibility. The 3‐alkynyl adducts, which are highly valuable substrates for diversity‐oriented synthesis, can be further transformed to useful carboline and carbazole derivatives through novel pathways.magnified image