Regioselective Intramolecular Allene Amidation Enabled by an EDA Complex*.

ABSTRACT

The addition of radicals to unsaturated precursors is a powerful tool for the synthesis of both carbo- and heterocyclic organic building blocks. The recent advent of mild ways to generate N-centered radicals has reignited interest in exploiting highly regio-, chemo-, and stereoselective transformations that employ these reactive intermediates. While the additions of aminyl, iminyl, and amidyl radicals to alkenes and alkynes have been well-studied, analogous additions to allenes are scarce. Allenes offer several attractive features, including potential for selective amidation at three distinct sites via judicious choice of precursor or radical source, the opportunity for axial-to-point chirality transfer, and productive trapping of vinyl or allyl radical intermediates to diversify functionality in the products. In this article, we report a regioselective addition of amidyl radicals to allenes to furnish an array of valuable N-heterocycle scaffolds.