Diaryliodonium Salts in Organic Syntheses: A Useful Compound Class for Novel Arylation Strategies

Abstract

This account aims to give a description of the usefulness of diaryliodonium salts in organic chemistry, including their synthesis and applications in the presence and absence of transition metal catalysts. Herein, we briefly summarize the structural properties and reactivity of diaryliodonium salts. We collected several applications of the hypervalent reagents including metal-free arylations of C, O, N and S nucleophiles. Synthesis and functionalization of aromatic and heteroaromatic systems via copper and palladium catalyzed transformations are also discussed in this account.

Heteroaryliodonium(III) Salts as Highly Reactive Electrophiles

“…It has gained great importance as a promising alternative to toxic heavy metal oxidants, such as Pb(IV), Tl(III), and Hg(II) because of its low toxicity, high stability, and easy handling (Stang and Zhdankin, 1996;Stang, 2002, 2008;Zheng et al, 2014;Yoshimura and Zhdankin, 2016). Diaryliodonium salts (Ar 1 Ar 2 I + X − ), which have two aryl groups and one counter-anion on the trivalent iodine atom, represent one of the most useful classes of hypervalent iodine(III) compounds (Merritt and Olofsson, 2009;Yusubov et al, 2011;Aradi et al, 2016;Fañanás-Mastral, 2017;Stuart, 2017). Due to the highly electron-deficient nature of the iodine(III) center in diaryliodonium salts and the excellent leaving-group ability of the iodobenzene group, they serve as highly reactive arylating agents toward a wide range of nucleophiles, even under metalfree conditions.…”

Copper-catalyzed O-alkenylation of phosphonates

“…Diaryliodonium and aryl(alkenyl)iodonium salts, which are airand moisture-stable, nontoxic and easy to prepare compounds, have become efficient reagents for mild and selective arylation and alkenylation reactions in organic synthesis [16][17][18]. In particular, the use of these hypervalent iodine reagents in copper catalysis has allowed to perform a wide range of previously unknown synthetic transformations [19][20][21][22][23][24][25][26][27][28][29].…”

Metal-free formal synthesis of phenoxazine

“…Our research group has reported highly efficient O -arylations of phenols using diaryliodonium salts [23–25], which are reactive electrophilic arylation reagents [26–28]. As diaryliodonium salts can be easily synthesized in a one-pot manner [28], we envisioned that phenoxazines could be obtained in a straightforward and efficient manner from commercially available starting materials.…”