N-Heterocyclic Iod(az)olium Salts - Potent Halogen-Bond Donors in Organocatalysis

This article describes the application of N-heterocyclic iod(az)olium salts (NHISs) as highly reactive organocatalysts. A variety of mono- and dicationic NHISs are described and utilized as potent XB-donors in halogen-bond catalysis. They were benchmarked in seven diverse test reactions in which the activation of carbon- and metal-chloride bonds as well as carbonyl and nitro groups was achieved. N-methylated dicationic NHISs rendered the highest reactivity in all investigated catalytic applications with reactivities even higher than all previously described monodentate XB-donors based on iodine(I) and (III) and the strong Lewis acid BF3.

Automated summary

The article explores the application of N-heterocyclic iod(az)olium salts (NHISs) as highly reactive organocatalysts, particularly as potent XB-donors in halogen-bond catalysis. Among the variety of NHISs tested, N-methylated dicationic NHISs exhibited the highest reactivity in all investigated catalytic applications, surpassing previously described monodentate XB-donors based on iodine(I) and (III) as well as the strong Lewis acid BF3.