l-Cysteine, a Versatile Source of Sulfenic Acids. Synthesis of Enantiopure Alliin Analogues

Abstract

[reaction: see text] l-Cysteine is a stimulating starting product for the generation of transient sulfenic acids, such as 4, 6, 9, and 15, which add to suitable acceptors, allowing formation of sulfoxides showing a biologically active residue. These sulfoxides are easily isolated in enantiomerically pure form. For instance, N-(tert-butoxycarbonyl)-l-cysteine methyl ester (1a) furnished in few steps sulfenic acid 9a, which was readily converted into (R,S(S))-(2-tert-butoxycarbonylamino-2-methoxycarbonyl-ethylsulfinyl)ethene (22), the methyl ester of Boc-protected nor-alliin. Moreover, the addition of 9a to 2-methyl-1-buten-3-yne has led to a sulfur epimeric and separable mixture of (R)-2-(2-tert-butoxycarbonylamino-2-methoxycarbonyl-ethylsulfinyl)-3-methyl-buta-1,3-dienes 10a and 11a, still possessing a "masked" sulfenic acid function, producible from their cysteine moieties once the dienes have been converted into the desired derivatives.

Strained Cycloalkynes as New Protein Sulfenic Acid Traps

“…Treatment of a thermally generated organic-soluble cysteine-derived sulfenic acid with 1 gives a mixture of diastereomeric alkenyl sulfoxides ( 2 ) as determined by NMR spectroscopy and liquid chromatography-mass spectrometry in 84% isolated yield (Figure 2). 12 Similar reaction of 1 with Fries acid, a stable anthraquinone-derived sulfenic acid, also produces the diastereomeric alkenyl sulfoxide ( 3 ) in 99% yield (Figure 2). 13 The results clearly show for the first time that this strained cycloalkyne reacts with small molecule model sulfenic acids in organic systems.…”

Type of complex–BSA binding forces affected by different coordination modes of alliin in novel water-soluble ruthenium complexes

“…In complexes (1) and 2 .0 ppm region. 14,37 The position of H6 signal in alliin and corresponding complexes (1) - 3is basically unchanged appearing in all cases in 5.4 -5.6 ppm region.…”

“…L-Deoxyalliin and (±)-L-Alliin were prepared by reported procedures with slight modifications. [35][36][37]…”

Design, synthesis and biological evaluation of sulfur-containing 1,1-bisphosphonic acids as antiparasitic agents

“…The controlled oxidation reaction of the corresponding thioethers is the most widely employed method of preparation of sulfoxides [56]. However, contrarily to what had been depicted in closely related compounds [57], in our hands all the attempts to oxidize any of the sulfides 22 – 30 by using sodium metaperiodate [58–60], hydrogen peroxide [61,62], or m -chloroperoxybenzoic acid [63] underwent a retro-Michael reaction. These results are in agreement with published data where alkylsulfides bonded at the β-position of aldehydes and ketones experienced a retro-Michael reaction when treated with an oxidizing agent affording the α,β-unsaturated carbonyl compounds and the corresponding alkylsulfanol [64–66].…”