37031-12-2Relevant articles and documents
Seleno-Michael Reaction of Stable Functionalised Alkyl Selenols: A Versatile Tool for the Synthesis of Acyclic and Cyclic Unsymmetrical Alkyl and Vinyl Selenides
Tanini, Damiano,Scarpelli, Simone,Ermini, Elena,Capperucci, Antonella
, p. 2337 - 2346 (2019)
Seleno-Michael additions of stable functionalised primary alkyl selenols to activated alkenes and alkynes are described. In the presence of Al2O3, β-hydroxy-, β-amino-, and β-mercapto selenols react smoothly with electron-poor alkenes and alkynes to afford the corresponding unsymmetrical functionalised dialkyl- and alkyl?vinyl-selenides in good yield. The very mild conditions allow a broad range of selenols and Michael acceptors to be converted into the corresponding synthetically valuable seleno-Michael adducts, demonstrating high selectivity and excellent functional group tolerance. Hydroxy- and mercapto-substituted vinyl selenides were efficiently employed for the synthesis of functionalised 1,3-oxaselenolanes, 1,3-thiaselenolanes, and 1,4-thiaselenanes through intramolecular oxa- and thia-Michael additions. Furthermore, a NaH-promoted lactonization enables the synthesis of variously substituted 2-oxo-1,4-oxaselenanes from hydroxy?vinyl-selenides. Evaluation of thiol peroxidase-like properties of novel functionalised organoselenides demonstrated that they possess a remarkable catalytic antioxidant activity. (Figure presented.).
Efficient resolution of oxidized Cleland's reagent by C2-symmetric BOC- L-phenylalanyl esters
Evans, Colleen A.,Bernier, Louise,Dugas, Josee,Mansour, Tarek S.
, p. 7657 - 7660 (1997)
Trans 4,5-dihydroxy-1,2-dithiane (1,oxidized form of Cleland's reagent; dithiothreitol) is resolved efficiently in > 99% overall e.e. into its two enantiomers by fractional recrystallization of its BOC-L-phenylalanyl diesters.
Click Reaction of Selenols with Isocyanates: Rapid Access to Selenocarbamates as Peroxide-Switchable Reservoir of Thiol-Peroxidase-Like Catalysts
Capperucci, Antonella,Petrucci, Alessandra,Faggi, Cristina,Tanini, Damiano
supporting information, p. 4256 - 4263 (2021/07/17)
Selenols react with isocyanates under mild catalyst-free conditions to generate selenocarbamates in good yield and with high selectivity over potentially competing nucleophilic additions. The methodology enables the incorporation of a wide variety of functional groups providing access to a broad array of densely functionalised selenocarbamates. In the presence of competing heteroatom-centered nucleophiles, isocyanates selectively couple with selenols. Selenocarbamates exhibited thiol-peroxidase-like properties, enabling the reduction of hydrogen peroxide at the expense of thiols, which are converted into the corresponding disulfides. A series of control experiments suggested that the catalytic mechanism proceeds through a pathway, involving a H2O2-promoted transcarbamoylation reaction leading to a thiocarbamate with concomitant releasing of catalytically active selenolate anions. By undergoing peroxide-driven thiol-selenol exchange, selenocarbamates behave as equivalents of selenolate anions with thiol-peroxidase-like activity. (Figure presented.).
Disulfide-Unit Conjugation Enables Ultrafast Cytosolic Internalization of Antisense DNA and siRNA
Shu, Zhaoma,Tanaka, Iku,Ota, Azumi,Fushihara, Daichi,Abe, Naoko,Kawaguchi, Saki,Nakamoto, Kosuke,Tomoike, Fumiaki,Tada, Seiichi,Ito, Yoshihiro,Kimura, Yasuaki,Abe, Hiroshi
supporting information, p. 6611 - 6615 (2019/04/10)
Development of intracellular delivery methods for antisense DNA and siRNA is important. Previously reported methods using liposomes or receptor-ligands take several hours or more to deliver oligonucleotides to the cytoplasm due to their retention in endosomes. Oligonucleotides modified with low molecular weight disulfide units at a terminus reach the cytoplasm 10 minutes after administration to cultured cells. This rapid cytoplasmic internalization of disulfide-modified oligonucleotides suggests the existence of an uptake pathway other than endocytosis. Mechanistic analysis revealed that the modified oligonucleotides are efficiently internalized into the cytoplasm through disulfide exchange reactions with the thiol groups on the cellular surface. This approach solves several critical problems with the currently available methods for enhancing cellular uptake of oligonucleotides and may be an effective approach in the medicinal application of antisense DNA and siRNA.
