Iron and Single Electron Transfer: All is in the Ligand

Abstract

This account describes some advances we have made in the field of iron catalysis. Two types of reactivity have been uncovered. Based on the use of an iron(II) precatalyst in the presence of NaBH 4 , the first one consists in a SET which can be useful for the reductive dehalogenation of iodide and bromide derivatives. Switching to the noninnocent bis-iminopyridine ligands promotes a previously undescribed Csp 2 ÀH activation reaction leading to biaryl derivatives. First clues into the intricate nature of the mechanism were obtained and suggested that the redoxactive bis-iminopyridine ligand acts as an electron reservoir. The resulting buildup of electron density triggers the CÀH bond breaking. All these findings are discussed in light of the existing literature and perspectives are given.