Ruthenium-Catalyzed Chemoselective N-H Bond Insertion Reactions of 2-Pyridones/7-Azaindoles with Sulfoxonium Ylides

A ruthenium-catalyzed highly chemoselective N-alkylation of 2-pyridones has been developed, affording N-alkylated 2-pyridone derivatives in good yields and excellent N-selectivity. The key to achieve this unprecedented N-H rather than O-H insertion reaction is the use of CpRu(PPh3)(2)Cl as the catalyst and sulfoxonium ylides as the alkylation reagents. Moreover, this protocol is also amenable to 7-azaindoles by slightly varying the reaction conditions. Furthermore, sulfonium ylides are also suitable alkylation reagents, providing the N-alkylated 2-pyridones in good selectivity.

Automated summary

A ruthenium-catalyzed highly chemoselective N-alkylation of 2-pyridones has been developed, providing N-alkylated 2-pyridone derivatives in good yields and excellent N-selectivity. The key to this unprecedented reaction is the use of CpRu(PPh3)(2)Cl as the catalyst and sulfoxonium ylides as the alkylation reagents, which can also be applied to 7-azaindoles with slight variations in reaction conditions. Furthermore, sulfonium ylides are also suitable alkylation reagents for good selectivity in N-alkylation of 2-pyridones.