Acid ionic liquid promoted addition of C(sp3)–H bond to aldehyde

A novel protocol for acid ionic liquid promoted C(sp3)–H bond functionalization of alkyl azaarenes and nucleophilic addition to aldehydes was developed in good to excellent yields, which provides an efficient approach for the synthesis of alkyl-substituted azaarene derivatives. It is worthwhile to note that acid ionic liquid used for this reaction can be recycled and reused six times without a significant decrease in activity.