Abstract Imines are fundamental building blocks in organic synthesis, and the development of efficient methods for their preparation remains an important challenge. Metathesis between the carbon–oxygen double bond (C=O) of carbonyl compounds and the carbon–nitrogen double bond (C=N) of isocyanates offers a promising route to imines. Herein, we report an Al/P FLP-catalyzed C=O/C=N metathesis that enables the synthesis of imines from aldehydes and isocyanates. Mechanistic investigations revealed that the unique catalytic activity of an Al/P FLP bearing two PCy2 groups arises from the presence of a non-coordinating PCy2 group, which facilitates catalyst regeneration from a resting state through reversible dissociation of the aldehyde adduct.
Okamoto et al. (Tue,) studied this question.