Metal- and additive-free oxygen-atom transfer reaction: an efficient and chemoselective oxidation of sulfides to sulfoxides with cyclic diacyl peroxides

Abstract

Metal- and additive-free oxidation of a series of sulfides/thioketones has been achieved using cyclic diacyl peroxides as mild oxygen sources. This protocol features simple manipulation, high chemo- and diastereoselectivity, and a broad substrate scope (up to 42 examples), tolerates many common functional groups, and is scalable and applicable to the late-stage sulfoxidation strategy. A preliminary mechanistic study by quantum mechanical calculations suggests that a single two-electron transfer process is energetically more favorable, and indicates the reactivity of cyclic diacyl peroxides distinct from conventional acyclic acyl peroxides.

The Chemistry of Peresters

“…It has been known for more than six decades that a cyclic diacyl peroxide, initially phthaloyl peroxide, achieved mild and stereoselective 1,2‐dioxygenation of alkenes . A recent renaissance in this area has focused on malonoyl peroxides (1,2‐dioxa‐3,5‐diones), which accomplish number of unique transformations under mild and metal‐free conditions: syn‐ or anti‐ dioxygenation of alkenes;, syn dioxygenation/oxidative dearomatization of e‐rich arenes; monooxygenation of arenes and C‐H activation of heteroarenes;, chemoselective oxidation of divalent sulfur; and, oxygenation of enol ethers and dicarbonyls , . We note that diacyl peroxides should be used with caution.…”

One pot synthesis of trifluoromethyl aryl sulfoxides by trifluoromethylthiolation of arenes and subsequent oxidation with hydrogen peroxide

“…Triuoromethyl suldes are less reactive for oxidation and various oxidizing agents such as m-CPBA, CF 3 CO 3 H, NaIO 4 , TCCA, cyclic diacyl peroxide, Oxone, MoO 2 Cl 2 (OPPH 3 ) 2 /Cu(NO 3 ) 2 have been used and only two examples with H 2 O 2 (F 20 TPPFe and TFA) were reported (Scheme 1). 3,[18][19][20][21][22] As triuoromethyl suldes are less reactive, selectivity of oxidation is problematic and overoxidation to sulfones occurs readily. The problem with most oxidants is the formation of toxic waste and environmentally harmful by-products (metal salts, reagent residues).…”

CoFe2O4@SiO2‐CPTES‐Guanidine‐Cu(II): A novel and reusable nanocatalyst for the synthesis of 2,3‐dihydroquinazolin‐4(1H)‐ones and polyhydroquinolines and oxidation of sulfides

“…Sulfoxides have very important structures because they contain S═O bonds and are privileged structural scaffolds for building pharmacologically and biologically active molecules as well as because of their unique properties, such as central chirality at the sulfur, high configurational stability and the strongly polarized S═O bond, which have attracted the attention of researchers. In addition, organic sulfoxides are used as versatile synthetic intermediates in the generation of numerous natural products and biologically active compounds …”