Synthesis of Azulen-1-yl Ketones via Oxidative Cleavage of C–C Multiple Bonds in <i>N</i>‑Sulfonyl Enamides and 1‑Alkynes under Air and Natural Sunlight

A synthetic method to prepare azulen-1-yl ketones was developed via oxidative cleavage of the C–C double bond in the reaction of easily obtainable <i>N</i>-sulfonyl enamides with Cs₂CO₃ under air and natural sunlight and in the absence of a photosensitizer. Oxidative cleavage of C–C triple bonds was also demonstrated for the synthesis of azulen-1-yl ketones via a tandem Cu-catalyzed [3 + 2] cycloaddition, Rh-catalyzed arylation, photooxygenation, and ring-opening reaction in one pot under air and natural sunlight

Diastereoselective <i>N</i>‑Sulfonylaminoalkenylation of Azulenes from Terminal Alkynes and Azides via<i> N</i>-Sulfonyl-1,2,3-triazoles

The development of rhodium-catalyzed diastereoselective <i>N</i>-sulfonylaminoalkenylation of azulenes using <i>N</i>-sulfonyltriazoles is described. This procedure can be successfully applied to rhodium-catalyzed diastereoselective <i>N</i>-sulfonylaminoalkenylation of azulenes starting from terminal alkynes and <i>N</i>-sulfonylazides via a three-component semi-one-pot process