Supramolecular Assemblies of Sulfur- and Selenium- Containing Expanded Porphyrins Mediated Through Noncovalent Interactions

Benzylic Thio and Seleno Newman–Kwart Rearrangements

“…Thiols and selenols play important parts in a range of chemistry, biochemistry, and materials applications. − Their uses as ligands in inorganic chemistry and as components in supramolecular assemblies are two central examples. − The subtle interplay between the thiol/disulfide and the selenol/diselenide through oxidation/reduction reactions is a defining trait of the chemical properties of these functional groups. − Prominently, both the thiol and selenol are parts of chiral amino acids as cysteine and selenocysteine, respectively. Selenocysteine is known as the 21st amino acid, and the role of selenocysteine (selenol) and selenocystine (diselenide) in protein function and structure is becoming increasingly recognized, as is the role of the more common cysteine/cysteine system. ,, The presence of selenocysteine is known to influence the catalytic properties of enzymes and can provide a means of altering the structural properties of the protein as compared to those of the corresponding proteins containing cysteine. ,, Native chemical ligation with selenocysteine is also known to be highly effective, − and selenols/diselenides are also efficient in catalyzing the disulfide exchange reaction …”