Bond-Forming and -Breaking Reactions at Sulfur(IV): Sulfoxides, Sulfonium Salts, Sulfur Ylides, and Sulfinate Salts

Abstract

Organosulfur compounds have long played a vital role in organic chemistry and in the development of novel chemical structures and architectures. Prominent among these organosulfur compounds are those involving a sulfur(IV) center, which have been the subject of countless investigations over more than a hundred years. In addition to a long list of textbook sulfur-based reactions, there has been a sustained interest in the chemistry of organosulfur(IV) compounds in recent years. Of particular interest within organosulfur chemistry is the ease with which the synthetic chemist can effect a wide range of transformations through either bond formation or bond cleavage at sulfur. This review aims to cover the developments of the past decade in the chemistry of organic sulfur(IV) molecules and provide insight into both the wide range of reactions which critically rely on this versatile element and the diverse scaffolds that can thereby be synthesized.

Metal-Bound or Free Ylides as Reaction Intermediates in Metal-Catalyzed [2,3]-Sigmatropic Rearrangements? It Depends.

“…Ylide formation can occur between a metal-carbene and a Lewis-basic heteroatom such as nitrogen, oxygen, sulfur, selenium, even iodine to form ammonium, 47 oxonium, 18,[48][49][50][51][52][53][54][55][56][57][58] sulfonium, [59][60][61][62][63][64][65][66] selenonium, [67][68][69] and iodonium ylides, 70 respectively (Scheme 1b). 71 Subsequent rearrangements (Doyle-Kirmse, Stevens, or Sommelet-Hauser) from the onium ylide can ensue thereafter (or not 63 ), and the type of rearrangement depends on the groups attached to the heteroatom.…”

A Ni–Ir Dual Photocatalytic Liebeskind Coupling of Sulfonium Salts for the Synthesis of 2‐Benzylpyrrolidines

“…In our research, we aimed to develop a method for the photocatalyzed coupling of sulfonium salts and N ‐protected proline to reach the desired target benzylpyrrolidines, and demonstrate the applicability of these onium reagents as coupling partners in dual photoredox transformations . Sulfonium salts are widely used versatile reagents in organic chemistry . Among these compounds, the tetrahydrothiophenium salts are capable of participating in cross‐coupling via oxidative addition reaction to palladium or nickel center as it was demonstrated by Liebeskind .…”

Site‐Selective Late‐Stage Aromatic [18F]Fluorination via Aryl Sulfonium Salts

“…The site-selective CÀHf unctionalization reaction developed herein exhibits broad substrate scope (Table 1). Both electron-poor (2, 21-23)a nd electron-rich (16, 24, 27)a renes proceed efficiently with high regioselectivity.V arious functional groups are well tolerated, including halides (2,(21)(22)(23)(24), nitriles (3), ethers (4)(5)20), esters (4, 10,15), ketones (5), aldehydes (7), amides (5,8,25), and sulfonamides (9,14). Heterocycles such as quinolines (12), imidazoles (19), and pyridines (20)a re also compatible.A renes that are more electron-deficient than 1,2-dichlorobenzene are too electronpoor to react.…”