Piperidine derivatives are particularly interesting compounds due to their versatile medicinal properties, e.g. as anticancer, antipsychotic and anti-Alzheimer agents. The introduction of such nucleophiles to iodonium salts 1 could hence be of special interest, and piperidine (2a) was chosen as the model substrate in reactions with 1a. To our delight, the desired product 3a was obtained in excellent yield under the conditions used in the previous isolation of SNAr intermediate A with water (EtOAc, 40 °C, 2 h), A small optimization study revealed that toluene was the superior solvent for most substrates (see SI, Table ). The substrate scope of salts 3 was first evaluated by varying aryl group Ar 2 , and both electron rich and electron deficient substituents in ortho-, para-and meta-position were tolerated, giving the corresponding products 3b-j in high to excellent yields (Scheme 2). Carbonyl containing aryl groups could be incorporated, as demonstrated by products 3i-j, and sterically congested Ar 2 were well tolerated (3k-3l). Variations on aryl group Ar 1 are more restricted, to retain the required SNAr reactivity of this moiety. Thus, we were pleased to see that the electron-withdrawing group (EWG) could be varied from nitro to other activating groups e.g. SO2CF3 and CN (3m, 3n), and allow for introduction of additional substituents such as CF3 (3o). Other cyclic amines, such as morpholine and thiomorpholine, were also productive in the reaction with salt 1a (3p, 3q). Additional functionality could be introduced by decorating amines 2 with a variety of functional groups (3r-3v), including a free hydroxyl group (3u). Also 5-and 7-membered cyclic amines 2 could be utilized, giving products 3w and 3x in 87% and 88% yield, respectively. Limitations of the scope were encountered with acyclic aliphatic amines, which underwent a competing reductive pathway (see SI, section 3.1). Since the synthesis of salts 3 was performed without excess reagents, the pure products were generally isolated after a simple filtration to remove the base residues. Next, the envisioned arylation/ ring-opening sequence was investigated using salt 3a and piperidine as the external nucleophile for the ring-opening of 4a, with the aim to install this valuable moiety at the end of the carbon chain of 5a (Table ). The synthesis of organic ammonium salts is generally difficult, and only a few examples are known in literature. Our key intermediate, ammonium salt 4, could be particularly challenging due to the high steric congestion from the two aryl moieties as well as the large ortho-iodo substituent. To our delight, the reaction proved to be possible using a mild base and no excess reagents, by heating salt 3a in MeCN at 100 °C for 4 h followed by reaction with K2CO3 and piperidine at rt for 2 h, to provide 5a as the only product in 47% yield (entry 1). Extension of the reaction time of step 1 to 16 h, to allow full formation of 4a prior to the piperidine addition, provided 5a in 93% yield (entry 2). Lowering the temperature had a negative impact on the yield (entry 3), as did using the other explored solvents and bases (entries 4-Scheme 2. Scope of diaryliodonium salts 3. a EtOAc as solvent. Performed at -78 °C to rt for 6 h. a Ar 1 = 2-iodo-4-nitrophenyl. b NMR yields with 1,3,5-trimethoxybenzene as internal standard. c Reaction performed without isolation of 3a. 9). While the full synthesis sequence from salt 1a to product 5a could be performed in one pot without isolation of 3a, the yields of 5a were considerably decreased (entry 10, see SI section 2.2.1 for further details).