1850-15-3Relevant articles and documents
Formation of acyldisulfide ions from the reaction of sulfur with thiocarboxylate ions, and reactivity towards acyl chlorides in N,N-dimethylacetamide
Robert, Julie,Anouti, Meriem,Paris, Jacky
, p. 473 - 478 (1997)
The reactivity of sulfur towards thiocarboxylate ions RC(O)S- a (R = Ph 1, Me 2, Bu′ 3) has been studied by spectroelectrochemistry in N,N-dimethylacetamide. For 2a-3a, two parallel and partial reactions, for which equilibrium constants have been determined, led to: (i) [RC(O)]2S2- b species and S3·-/S82- polysulfide ions and (ii) RC(O)S2 ions c; only traces of 1c were detected by voltammetry. As previously observed with thiolate ions, our results are consistent with an initial monoelectronic transfer between RC(O)S- ions and S2 molecules in equilibrium with S8, followed by concurrent couplings of RC(O)S· and S2·- radicals. On a preparative scale, when sulfur was added to RC(O)S- ions 1a,3a the enhanced reactivity of RC(O)S2- ions towards acyl chlorides RC(O)Cl (R = C6H5 and Bu′, respectively) only yielded diacyl disulfides 1b,3b.
Nucleophilic substitution of acyl chlorides by electrogenerated polysulfide ions in N,N-dimethylacetamide
Robert, Julie,Anouti, Meriem,Abarbri, Mohamed,Paris, Jacky
, p. 1759 - 1764 (1997)
The reactions between acyl chlorides RC(O)Cl (a) [R = Me (1), Pri (2), Bui (3), Ph(4)] and electrogenerated S3._(? S62-) ions have been investigated in N,N-dimethylacetamide by spectroelectrochemistry. With R = alkyl, thiocarboxylate ions and sulfur resulting from the fast initial substitutions cause partial formation of both acyl disulfide ions and diacyl disulfides (b) at a y ratio [RC(O)C1]/[S3._] of 0.5; the second step stoichiometrically (y = 1) affords diacyl disulfides 1b-4b as the presumed products. The formation of these species only is confirmed on a preparative scale from two sets of experiments: (i) direction addition of acyl chlorides (1a-4a) to chemically generated S1/3- solutions; (ii) electrolysis of sulfur in the presence of acyl chlorides 2a-4a.
Exploration of an imide capture/N,N-acyl shift sequence for asparagine native peptide bond formation
Mhidia, Reda,Boll, Emmanuelle,Fécourt, Fabien,Ermolenko, Mikhail,Ollivier, Nathalie,Sasaki, Kaname,Crich, David,Delpech, Bernard,Melnyk, Oleg
supporting information, p. 3479 - 3485 (2013/07/05)
Imide capture of a C-terminal peptidylazide with a side-chain thioacid derivative of an N-terminally protected aspartyl peptide leads to the formation of an imide bond bringing the two peptide ends into close proximity. Unmasking of the Nα protecting group and intramolecular acyl migration results in the formation of a native peptide bond to asparagine.