Enantiopure sulfoxides: recent applications in asymmetric synthesis

Abstract

Sulfoxides are nowadays recognised as powerful chiral auxiliaries that may participate in a wide range of asymmetric reactions. Their high configurational stability, the existence of several efficient methods allowing the access to both configurations as well as their synthetic versatility are characteristic features offering a tremendous potential to develop new applications. Significant recent advances leading to high asymmetric inductions in carbon-carbon and carbon-oxygen bond forming reactions, and applications of homochiral sulfoxides to atroposelective synthesis and asymmetric catalysis are discussed. New uses of sulfoxides in the design of chiroptical switches are also shown.

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

“…Focusing on the four major groups of organosulfur(IV) compounds carrying S–C and S–O bonds, namely sulfoxides, sulfonium salts, sulfur ylides, and sulfinate salts, this review article aims to provide an overview of a decade of research up to October 2018 that has led to the development of novel reactions and the enhancement of pre-existing protocols and textbook transformations. We center our attention on reactions that involve either bond formation or bond cleavage at sulfur, thereby excluding sulfoxide-based ligands and auxiliaries (both previously reviewed: refs (17), (18), and (19) as well as (20) and (21), respectively). Additional classes of sulfur species carrying bonds to other elements (such as the S–N of sulfylimines) are not covered.…”

Stereoselective synthesis of unnatural α-amino acid derivatives through photoredox catalysis

“…13 a The developed catalytic system made use of a chiral sulfoxide auxiliary group, commonly employed in the synthesis of chiral amines. 14 Here, the C-centered radical was generated through visible light-mediated reductive cleavage of the N–O bond in a redox-active phthalimide ester, followed by radical addition to the N -sulfinyl imine. The reductive nature of this protocol required the use of a stoichiometric amount of a reducing agent (Hanztsch ester).…”

Highly Efficient Access to (S)‐Sulfoxides Utilizing a Promiscuous Flavoprotein Monooxygenase in a Whole‐Cell Biocatalyst Format

“…Chiral sulfoxides have gained huge attention as synthons and precursors for the synthesis of APIs, flavors and fragrances, or as chiral auxiliaries in chemical syntheses . As the potency of one enantiomer often outperforms the one of the antipode (e. g., shown for esomeprazole), enantiopure sulfoxide preparation is required.…”