Iodonium Salts as Benzyne Precursors

Abstract

Reactions involving benzyne and aryne intermediates have found widespread application in organic synthesis. Various benzyne precursors and benzyne generating procedures are known. Recently, methods of benzyne generation from diaryliodonium salts and related hypervalent iodine compounds have received considerable attention. These methods are characterized by mild reaction conditions and applicability in a broad range of chemical transformations. The present minireview is focused on the preparation and reactivity of hypervalent iodine based benzyne precursors. Furthermore, recent developments in their synthetic application are discussed.

Dataset on synthesis and crystallographic structure of phenyl(TMP)iodonium(III) acetate

“…Recently, utilization of the auxiliary and the dummy ligand in diaryliodonium (III) salts for a selective aryl-transfer has been actively investigated after the discovery of Mes-iodonium (III) salts (Mes = mesityl) [2] , [3] . The organic salts consisting of phenyl (TMP)iodonium (III) cation (TMP = 2,4,6-trimethoxyphenyl) and the counterion, such as Cl − [4] , [5] , Br − [4] , BF 4 − [4] , TfO − [4] , [6] , TsO − [7] , and CF 3 COO − [8] , serve as efficient aryl-transfer reagents for metal-free coupling reactions [9] , [10] , [11] . In our work, the aryl (TMP)iodonium (III) salts were applied as the efficient arylating agents for the copper-catalyzed N -arylation of azole compounds, which turned out that these iodonium (III) salts have high reactivities even in the metal-catalyzed coupling together with the reported exclusive aryl-group transfer behavior [1] .…”

2-Iodoxybenzoic acid ditriflate: the most powerful hypervalent iodine(v) oxidant

“…In recent years, the interest in synthetic applications of hypervalent iodine compounds as versatile oxidizing reagents and catalysts has experienced an explosive growth. [1][2][3][4][5][6][7][8][9] Hypervalent iodine(V) reagents represent a particularly important class of oxidants extensively employed in organic synthesis. 2-Iodoxybenzoic acid (IBX, structure 1 in Fig 1) and the product of its acetylation Dess-Martin periodinane (DMP, 2) have become the most common oxidizing reagents used for selective oxidation of alcohols to carbonyl compounds and other synthetically useful oxidative transformations.…”

Salts in Organic Synthesis: An Overview and Their Diversified Use

“…Various papers are published by discussing the role of individual salts, their selective way of transformation, role in asymmetric synthesis and many more. Some of the recent influencing research on application of salts in organic synthesis are use of diaryliodonium salts for novel arylation [20], applications of ferrocenium salts [21], salt as linker source [22], pyridinium salts as radical reservoir [23], use of vinyliodonium salts for alkenylation of nitriles [24], use of sulfonium salts for synthesis of spirocyclopropanyl paradienones [25], use of phosphonium salts for selective functionalization of pyridines [26], tropylium salts as lewis acid to catalyze acetalization and transacetalization [27], use of Phenyltrimethylammonium salts in nickel-catalyzed methylation of C− H bonds [28], aryldiazonium salts for carbohydroxylation of styrenes [29], synthesis of bicyclic aziridines from pyridinium salts [30], nucleophilic arylation with tetraarylphosphonium salts [31], application of trimethylsilanolate alkali salts in organic synthesis [32], use of α, β-unsaturated acylammonium salts for asymmetric organocatalysis [33], review on cesium salts use in organic synthesis [34], iodonium salts as benzyne precursors [35], use of bunte salts as a sulfur source for synthesis of 3-thioindoles [36], and C− H functionalization of arenes by diaryliodonium salts [37] etc.…”