Design, synthesis and glutathione peroxidase-Like properties of ovothiol-Derived diselenides
摘要:
Eleven imidazole diselenides derived from the naturally occurring family of antioxidants, the ovothiols, were synthetised by cyclisation of selenoamides with trimethylsilyltrifluoromethanesulfonate or refluxing of cyanoamines in a selenium/sodium borohydride mixture. These compounds were assayed for their glutathione peroxidase-like (GSH Px-like) activity and their capacity to be reduced by glutathione. The most active molecules of the series were 4 times more potent in the GSH Px-like test than the widely known reference compound, ebselen. This catalytic activity was mediated by the formation of the antioxidant selenol intermediate upon partial but significant exchange reaction with glutathione. (C) 2003 Elsevier Ltd. All rights reserved.
Copper-Catalyzed Three- Five- or Seven-Component Coupling Reactions: The Selective Synthesis of Cyanomethylamines, N,N-Bis(Cyanomethyl)Amines and N,N'-Bis(Cyanomethyl)Methylenediamines Based on a Strecker-Type Synthesis
We have demonstrated that a cooperative catalytic system comprised of CuCl and Cu(OTf)2 could be used to effectively catalyse the three-, five- and seven-component coupling reactions of aliphatic or aromatic amines, formaldehyde, and trimethylsilyl cyanide (TMSCN), and selectively produce in good yields the corresponding cyanomethylamines, N,N-bis(cyanomethyl)amines and N,N'-bis(cyanomethyl)methylenediamines.
Eleven imidazole diselenides derived from the naturally occurring family of antioxidants, the ovothiols, were synthetised by cyclisation of selenoamides with trimethylsilyltrifluoromethanesulfonate or refluxing of cyanoamines in a selenium/sodium borohydride mixture. These compounds were assayed for their glutathione peroxidase-like (GSH Px-like) activity and their capacity to be reduced by glutathione. The most active molecules of the series were 4 times more potent in the GSH Px-like test than the widely known reference compound, ebselen. This catalytic activity was mediated by the formation of the antioxidant selenol intermediate upon partial but significant exchange reaction with glutathione. (C) 2003 Elsevier Ltd. All rights reserved.
Strecker Reactions of Formaldehyde with TMSCN, Catalyzed by TBAF and Formic Acid:
<i>N</i>
‐Monocyanomethylation of Primary Amines
Strecker reaction of formaldehyde, amines, and TMSCN that affords three-component coupling adducts as the major products is reported. HCOOH and TBAF are used as cocatalysts and the TMSCN functions as both cyanidesource and protecting reagent for amines. As a result, the side reactions were suppressed efficiently and a broad range of aromatic and aliphatic amines were mono-cyanomethylated in 52–99%