Synthesis of Naphthalimides through Tandem Pd(II)-Catalyzed C(sp3)–H Oxidation and Diels–Alder Reaction Using a Transient Directing Group Strategy

Naphthalimideshave found extensive applications in materials scienceand pharmaceuticals. It is still highly desirable to develop efficientmethods for the synthesis of naphthalimides with structural diversity.In this work, we developed a new approach for the synthesis of naphthalimidesvia a tandem reaction of o-methylbenzaldehydes andmaleimides. The tandem reaction involves Pd(II)-catalyzed benzylicC(sp(3))-H oxidation using an amino acid as the transientdirecting group and Diels-Alder reaction. The subsequent dehydrationforms naphthalimides. The reaction introduces the imide moiety andconstructs a benzene ring simultaneously, allowing for easy accessto a range of naphthalimides with a variety of substituents.