Intramolecular Pd-Catalyzed Reductive Amination of Enolizable sp³-C–H Bonds

Abstract

A palladium-catalyzed reductive cyclization of nitroarenes has been designed to construct sp³-C-NHAr bonds from sp³-C-H bonds by using an enolizable nucleophile to intercept a nitrosoarene intermediate. Exposure of <i>ortho</i>-substituted nitroarenes to 5 mol % of Pd(OAc)₂ and 10 mol % of phenanthroline under 2 atm of CO constructs partially saturated 5-, 6-, or 7-membered <i>N</i>-heterocycles using α-pyridyl carboxylates, malonates, 1,3-dimethylbarbituric acid, 1,3-diones, or difurans as the nucleophile.