The unique alkene hydronitration reaction raises two important mechanistic questions (Figure ): (1) Is this conventional MHAT reactivity 20 (Path A, Figure ) or does the reagent act as an oxidant in a radical polar crossover pathway (Path B, Figure )? and (2) what is special about reagent 16 that favors N vs. O addition (Figure )? To address the first question, during the course of this study etherification byproducts from interception of a putative carbocation with i-PrOH were never detected. Even when intramolecular ether formation was possible in the reaction of olefin 76, ether product 77 was not observed. Although this is not definitive proof of the mechanism, taken together with the vast body of MHAT literatures, a standard radical pathway is presumably operative. With regards to the second question, a series of computational experiments on all of the tested nitrating agents (Table ) were conducted. No correlation could be identified with regards to N-NO2 bond length or O-N-O bond angles to explain the disparate results (see SI for details). At the moment our best hypothesis is that the presence of two ortho-CF3 groups somehow shield the oxygen atoms of the pendant nitro group thereby favoring radical attack at nitrogen (Figure , compare X-ray crystallographic structures of 16 to 35B). Indeed, X-ray crystallographic analysis revealed that reagent 16 adopts a more cup-like shape shielding the oxygen atoms (an electrostatic interaction of the oxygen atoms to the CF3 groups is possible) on the nitro group relative to mono-CF3-containing reagent 35B (compare 121.5° to 116.9° angles of the C-C-N bonds in 16 and 35B, respectively). Finally, nitroamide 16 is an air-and bench-stable powder and its thermal stability was studied using differential scanning calorimetry (DSC) analysis, revealing an onset temperature around 180 o C (see SI for DSC spectra). Based on the Yoshida correlation (see SI), reagent 16 is therefore not predicted to be either explosive or shock sensitive.