Vinyl‐/Furoindoles and Gold Catalysis: New Achievements and Future Perspectives for the Synthesis of Complex Indole Derivatives

Abstract

The reactivity of vinyl‐/furoindole derivatives with gold‐activated π‐systems is the subject of extensive investigation. In the presence of these electrophilic partners, the realized transformations allow for the construction of different and fascinating architectures via cycloaddition and cyclization reactions often included in cascade processes. The reactions realized involving in these processes an external substituent at the indole moiety are the subject of the present minireview.

Au(III) catalyzes the cross-coupling between activated methylenes and alkene derivatives

“…Gold catalysis is one of the most captivating topics in Organic Chemistry [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. In recent years, particular attention has been devoted to gold catalyzed CAH bond activations as a strategic tool for the formation of new CAC bonds.…”

Chiral Phosphathiahelicenes: Improved Synthetic Approach and Uses in Enantioselective Gold(I)-Catalyzed [2 + 2] Cycloadditions of N-Homoallenyl Tryptamines

“…Next, to take full advantage of this potential, we decided to go beyond model catalytic reactions on known substrates and we turned our attention to some unprecedented gold-catalyzed transformation of indoles. Indeed, indole derivatives are known to afford numerous interesting polycyclic products under gold catalysis. , Notably, over the last few years, we have been involved in the development of gold-catalyzed spirocyclizations of indoles, leading to a range of spirooxindoles and spiroindolenines. , In particular, we disclosed recently the first regioselective spirocyclizations of the N -propargyltryptamines 16 into C2-unsubstituted spiroindolenines (Scheme a). An enantioselective version of this reaction showed only moderate enantioselectivity, with the use of HelPhos-S-AuCl as the gold precatalyst (60% ee) .…”

“…Formation of the first carbon–carbon bond by the nucleophilic addition of indole to the activated allene leads to the spiranic intermediate II with concomitant dearomatization of the indole. Analogous 6- exo cyclizations involving nucleophilic indoles and tethered unsaturated functions, activated by gold, are quite common with this class of tryptamine derivatives. , A consecutive intramolecular addition of the vinyl–gold species to the indolenium electrophilic site then affords the 2,3-indoline-fused cyclobutane product 19 , while releasing the active gold complex.…”