Consecutive formation of CN and CS bonds: The gold‐catalyzed intramolecular aminosulfonylation of 2‐alkynyl‐N‐sulfonylanilines 1 (R1=H) produces 3‐sulfonylindoles 2 in good to high yields, whereas the indium‐catalyzed aminosulfonylation of 2‐alkynyl‐6‐methoxy‐N‐sulfonylanilines 1 (R1=MeO) affords 6‐sulfonylindoles 3 as the major products (see scheme).

Aufeinander folgende C‐N‐ und C‐S‐Verküpfungen durch intramolekulare Aminosulfonylierung: Die goldkatalysierte Reaktion der 2‐Alkinyl‐N‐sulfonylaniline 1 (R1=H) ergibt 3‐Sulfonylindole 2 in guten bis hohen Ausbeuten, die Umsetzung von 2‐Alkinyl‐6‐methoxy‐N‐sulfonylanilinen 1 (R1=MeO) in Gegenwart von InBr3 führt hingegen zu 6‐Sulfonylindolen 3 als Hauptprodukten (siehe Schema).

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Gold-catalyzed reactions of ortho-alkynyl-N-sulfonylanilines produced the corresponding 3-sulfonylindoles in good to high yields. For example, the reaction of N-mesyl-N-methyl-2-(1-pentynyl)aniline, N-mesyl-N-methyl-2-(phenylethynyl)-aniline, and 2-ethynyl-N-mesyl-N-methylaniline in the presence of 10 mol % of AuBr3 in toluene at 80 degrees C gave 3-mesyl-1-methyl-2-propylindole, 3-mesyl-1-methyl-2-phenylindole, and 3-mesyl-1-methylindole in 95, 92, and 71% yield, respectively. Furthermore, we found that the reactions of 2-alkynyl-6-methoxy-N-sulfonyl-anilines in the presence of indium catalyst (InBr3) afforded the corresponding 6-sulfonylindoles as the major product in good yields. For example, the reaction of 6-methoxy-N-methyl-2-(1-pentynyl)-N-tosylaniline in the presence of 5 mol % of InBr3 in toluene at 80 degrees C gave an 87:13 mixture of 7-methoxy-1-methyl-2-propyl-6-tosylindole and 7-methoxy-1-methyl-2-propyl-3-tosylindole in 95% yield. Most probably, the gold-catalyzed reactions of ortho-alkynyl-N-sulfonylanilines proceed through a [1,3] sulfonyl migration, whereas the indium-catalyzed cyclizations of 2-alkynyl-6-methoxy-N-sulfonylanilines, which produce 6-sulfonylindoles, proceed by an unprecedented [1,7] sulfonyl migration.

The allylation of various pronucleophiles 1a–i with 1‐phenylprop‐1‐yne (2) proceeded very smoothly at 50 °C in the presence of catalytic amounts of Pd2(dba)3·CHCl3 (5 mol‐%) and 2‐(dicyclohexylphosphanyl)‐2′‐(dimethylamino)biphenyl (I; 20 mol‐%) in toluene, whilst when Pd(PPh3)4 or Pd2(dba)3·CHCl3/PPh3 were used, the reaction needed 100 °C for completion.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)