Transition-Metal-Free Alkylation and Acylation of Benzoxazinones with 1,4-Dihydropyridines

The direct functionalization of N-heterocycles
is a vital transformation for the development of pharmaceuticals,
functional materials, and other chemical entities. Herein, the transition-metal-free
alkylation and acylation of C­(sp2)–H bonds in biologically
relevant 2-benzoxazinones with 1,4-dihydropyridines as readily accessible
radical surrogates is described. Excellent functional group compatibility
and a broad substrate scope were attained. Gram-scale reaction and
transformations of the synthesized adducts via Suzuki coupling with
heteroaryl boronic acids demonstrated the synthetic potential of the
developed protocol.