Hypervalent iodide (HVI) reagents have been shown to be useful in synthetic organic transformations ranging from oxidations to C-C bond formation. Many of these transformations use the commercially available hypervalent iodine(III) reagent phenyliodonium diacetate (PIDA). While popular, PIDA does not have a great solubility profile in less polar solvents (e.g., it is insoluble in hexanes) and is generally only used in CH₂Cl₂ and acetonitrile. Poor solubility results in a limited number of solvents that can be screened to accomplish a desired transformation. Reagents with better solubility profiles allow for more thorough optimization as well as greener transformations due to less solvent required to dissolve the reagents. Increasing the solubility of iodonium reagents in water has been accomplished but reagents that are more soluble in non-polar solvents remains understudied.
In a previous publication, our laboratory disclosed reagent 1a (Figure 1) which had increased solubility in hexanes (1.94 x 10^–2 mmol/mL) compared with PIDA which is insoluble in hexanes. We have designed and synthesized reagents 1b through 1e to have an even increased solubility in hexanes. Compounds 1b to 1d are all liquid reagents, which have beneficial properties over solids in applications such as flow chemistry. Relative solubilities of liquid reagents were determined by obtaining the distribution coefficients of the reagents between acetonitrile and hexanes. The new reagents were tested against PIDA for reactivity in carbon-carbon bond forming reactions.

Christina Callovi

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