Unique performance: Bi‐, ter‐, and quater‐heteroaryls have been prepared under indium catalysis by nucleophilic aromatic substitution (SNAr). This is the first example of catalytic heteroaryl–heteroaryl bond formation based on SNAr between two heteroaryl substrates without needing activating groups to enhance their reactivity (see scheme; El=electrophile, In=In(OTf)3 or In(ONf)3, Nu=nucleophile).

Heteroarene sind reaktiv genug: Bi‐, Ter‐ und Quaterheteroaryle wurden durch nucleophile aromatische Substitutionen (SNAr) unter Indiumkatalyse erhalten. Damit gelang erstmals die katalytische Verknüpfung von zwei Heteroarylsubstraten ohne aktivierende Gruppen durch SNAr‐Substitution (siehe Schema; El=Elektrophil, In‐Kat.=In(OTf)3 oder In(ONf)3, Nu=Nucleophil).

In most cases, In(O‐Tf)3 is found to be the optimal catalyst.

Nucleophilic reaction of Grignard reagents with the 4‐hydroxybutenolides (I) represents a facile and reliable method for the preparation of 4‐alkyl derivatives (14 examples given in all).