Oxy‐ and Chloroarylation Pathways in Gold‐Mediated Cyclization of 2‐Aminoaryl‐3‐arylpropargyl‐benzenesulfonamides

Abstract

We described herein a one‐pot diazotization/gold‐mediated cyclization of 2‐aminoaryl‐3‐arylpropargyl‐benzenesulfonamides. After diazotization, Me2SAuCl triggers an oxy‐ and/or chloroarylation of the alkyne moiety, resulting in the formation of 3‐acylindoles and/or Z‐3‐(chloromethylene)indolines. Density Functional Theory (DFT) calculations show the significant energetic preference of both processes over an insertion pathway. Notably, a Z‐3‐(chloromethylene)indoline crystallized with [Cl‐Au‐Cl],‐ exhibiting Au⋅⋅⋅H‐C short contacts.

Straightforward Access to Isoindoles and 1,2-Dihydrophthalazines Enabled by a Gold-Catalyzed Three-Component Reaction

“…We have observed that simple Au­(I) precursors undergo the oxidative addition with aryldiazonium salts, either under thermal conditions or in the presence of catalytic amounts of ascorbic acid. By applying these protocols, we have successfully synthesized various small arylated molecules such as diarylalkylidene lactones, 2-arylindoles, 3,4-diaryl-2 H -chromenes, biaryls, biarytioethers, 3-(chloro­(aryl)­methylene)­indolines and 3-benzoylindoles . Due to our experience with gold-mediated or catalyzed arylation reactions and inspired by the reactivity possibilities exhibited by benzo-fused enynals/enynones, we got interested in developing a one-pot gold-catalyzed cyclization/nucleophilic addition/arylation reaction.…”