Regiospecific Reductive Elimination from Diaryliodonium Salts

Abstract

StereoElectronic Control of Unidirectional Reductive Elimination (SECURE) is provided by the cyclophane substituent on iodine(III). Computational and experimental studies demonstrate that out of plane steric bulk strongly destabilizes the reductive elimination transition state, and leads to regiochemical control. This approach should be general for high valent main group and transition metal ions.

Spirocyclic hypervalent iodine(III)-mediated radiofluorination of non-activated and hindered aromatics

“…As shown in Fig. 2a, the extent of such stabilization should still enable the formation of 18 F-labelled products via the addition/reductive elimination mechanism 16,24 that has been invoked for diaryliodonium salts and other I(III) species [15][16][17]20,25,26 . Initial experiments (Fig.…”

Reductive Eliminations from λ3-Iodanes: Understanding Selectivity and the Crucial Role of the Hypervalent Bond

“…1 The computed barrier leading to the anti product is 2.05 kcal/mol lower in energy, showing that the anti product is favored over the syn product, and reflects the experimental ratio of 9:1 (see Table 1). The selectivity With a 3cÀ4e bond involved in both reductive elimination reactions, its features are likely to influence the selectivity observed.…”

Solid‐Supported Iodonium Salts for Fluorinations

“…Investigation begun with the attempted production of solid-supported diaryliodonium salts previously reported in a patent by Carroll et al [9] The strategy uses amide bond formation as the key step, linking the precursor to the resin. Aminomethyl-functionalised polystyrene resin is used for coupling to carboxylic acids 1 and 2(TFA) (Figure 1).…”

“…Other non-participating groups include a [2,2]paracyclophane moiety. [9] Adaption of this methodology to solid-supported iodonium salts for the introduction of fluorine combines the rapid and selective fluorination of diaryliodonium salts with the facile purification available to solid-supported precursors. Work in this area includes radiofluorination of solidsupported iodonium salt precursors for the production of [ 18 F]fluorobenzene and […”