Our initial experiments to probe this hypothesis focused on the use of zinc powder, without any further additives classically used to aid the generation of such reagents, to form the corresponding pyridyl-zinc iodide (Fig. ). We were pleased to observe that stirring a mixture of N-methylbenzylamine (1a), hydrocinnamaldehyde (2a) and 2-iodopyridine (3a) in a dichloromethane solution with 1.5 equivalents of zinc powder and trimethylsilyl trifluoromethanesulfonate (TMSOTf, to facilitate iminium ion formation) at room temperature afforded α-substituted 2-pyridyl amine 4a in 16% assay yield (AY), as determined by 1 H NMR spectroscopy (Table , entry 1). Raising the temperature of the reaction resulted in only trace amounts of the desired product being formed (entry 2) and no significant benefit was observed when changing the equivalents of Zn (entries 3 & 4). We noted that the use of indium powder, whose first ionization potential of +5.8 eV indicates a good single electron reductant (compare with that of Na [+5.1 eV] and Zn [+9.4 eV]), gave comparable yields to those obtained with zinc (entry 5, also see Supplementary Information, Table ), and when the reaction was stirred at elevated temperature a substantially higher yield of 4a was obtained (see Supplementary Information, Table ). Following further exploration of the reaction parameters around this lead result, a set of optimal conditions were identified that consistently produced high assay yields of the desired amine 4a (entry 6): vigorous stirring of a 1,4-dioxane solution containing amine 1a (1 equiv.), aldehyde 2a (1.5 equiv.), 2-iodo pyridine 3a (2 equiv.), indium powder (1.5 equiv.) and TMSOTf (1.5 equiv.) at 70 ˚C for 8 h afforded amine 4a in 85% assay yield, which after isolation and purification by silica gel chromatography provided 67% yield of the desired product. A cursory screen of alternate Lewis and Brønsted acids revealed a particular dependence on the use of TMSOTf (entries 7-8, also see Supplementary Information, Table ). Control experiments revealed that both indium and TMSOTf were vital for the success of the reaction (entries 9-10). We believe that TMSOTf is playing multiple roles in the reaction, including aiding iminium ion formation, enhancing the reactivity of the carboniodine bond through coordination to the adjacent pyridine nitrogen and activating the indium metal (see Supplementary Information, Section 9.1). Under the optimized conditions a reaction using 2-bromopyridine gave an assay yield of 20% and no product was formed with 2-chloropyridine (returning only the starting material) highlighting the importance of the 2-iodo group and the relative reactivity of the weaker carbon-iodine bond with respect to indium insertion.