Synthesis of Sulfoxides by the Hydrogen Peroxide Induced Oxidation of Sulfides Catalyzed by Iron Tetrakis(pentafluorophenyl)porphyrin: Scope and Chemoselectivity.

Abstract

Synthesis of Sulfoxides by the Hydrogen Peroxide Induced Oxidation of SulfidesCatalyzed by Iron Tetrakis(pentafluorophenyl)porphyrin: Scope and Chemoselectivity. -The title reaction A) offers a mild, general, fast, and chemoselective approach to sulfoxides. Using 2 equiv. of H2O2 and higher amounts of catalyst [cf. conditions B)], efficient and selective formation of sulfones is possible. However, starting from the cyclic sulfides (VIII) sulfones are not obtained. Instead, 1,3-dioxides are formed. -(BACIOCCHI*, E.; GERINI, M. F.; LAPI, A.; J.

Porphyrins as Catalysts in Scalable Organic Reactions

“…One successful example of a green protocol was described by Baciocchi and co-workers, who reported the oxidation of sulfides with an ethanolic solution of H 2 O 2 and iron tetrakis(pentafluorophenyl)porphyrin as catalyst, thus giving the corresponding sulfoxides on a gram-scale (Scheme 9) [53].…”

“…Sulfoxidation is commonly presented as being a direct pathway for generating sulfoxides, however, most of the reagents used for this reaction such as iodosylbenzene, peroxyacids, and stoichiometric oxo-metal oxidants are unsatisfactory due to their high toxicity and low chemoselectivity between sulfoxide and sulfone products [52]. One successful example of a green protocol was described by Baciocchi and co-workers, who reported the oxidation of sulfides with an ethanolic solution of H2O2 and iron tetrakis(pentafluorophenyl)porphyrin as catalyst, thus giving the corresponding sulfoxides on a gram-scale (Scheme 9) [53]. Among the methods to obtain sulfoxides [54], the enantioselective oxidation of sulfides with small amounts of metal-organic catalysts is one of the most attractive routes to optically active sulfoxides [55].…”

Vinyl Sulfone: A Multi-Purpose Function in Proteomics

“…When the elimination step is firstly performed (route a), the vinyl thioether intermediate obtained can be easily oxidized to the corresponding vinyl sulfones by common oxidizing agents (H 2 O 2 -acetic acid, m-chloroperbenzoic acid -mCPBA-or periodic acid -HIO 4 -) or the commercial Oxone reagent. The slow kinetic showed by the method based in H 2 O 2 (Bordwell & Pitt, 1955) has been overcome by the concomitant use of some catalysts (MnSO 4 or tetrakis(pentafluorophenyl)porphyrin) in order to exploit the goodness of this methodology: low cost and toxicity, and high yields (Alonso et al, 2002;Baciocchi et al, 2004). In the alternative sequence (route b), the sulfone is obtained previously by using the reagents just mentioned followed by the elimination step that is favoured by the strong electron-withdrawing effect of the sulphur function, being only necessary a weak base (triethylamine) in case of the dehydrohalogenation (Brace, 1993) or the conversion on a good leaving group, usually a sulfonic ester, in the dehydration option (Lee et al, 2000;Galli et al, 2005).…”

Biomimetic Sulfide Oxidation by the Means of Immobilized Fe(III)‐5,10,15,20‐tetrakis(pentafluorophenyl)porphin under Mild Experimental Conditions

“…Such a problem of incomplete oxidation simply does not exist in the case of thiols (mercaptans) that are easily and cleanly oxidized to the corresponding sulfonic acids [31]. Organic sulfides (thioethers) are converted to the corresponding sulfones upon oxidation [32], also under metalloporphin catalysis [33][34][35][36]. Therefore, clean oxidation of hydrogen sulfide in water to sulfate under mild operative conditions is a serious challenge.…”