Unexpected Squaramide‐Induced Cleavage of Benzils: Synthesis and Characterization of Mono‐Aroyl Squarimides

Abstract

We report the reaction of 4,4′‐substituted benzils with squaramides (SQ) affording mono‐squarimides (SQIs). The 1H NMR and X‐ray structures of the SQIs (R = H) revealed the existence of a strong C=O···HN intramolecular hydrogen‐bond motif. The unprecedented reaction between SQs and benzils highlights the difference in reactivity between urea and squaramide units.