7783-42-8Relevant articles and documents
Vanadium, niobium and tantalum complexes with terminal sulfur radical ligands
Chen, Xiuting,Gong, Yu,Hu, Jingwen,Wei, Rui
, p. 11300 - 11306 (2021)
Sulfur radicals terminally bound to the metal center can be considered as the one-electron reduction products of complexes with terminal sulfido ligands which serve as the reactive sites in enzymes and precursors. However, there is limited information regarding this kind of metal stabilized sulfur radical, which contrasts the more commonly known metal stabilized thiyl radical. In this work, we report the preparation of vanadium, niobium and tantalum radical complexes in the form of M(O)(S)F2 from the reactions of laser-ablated metal atoms and SOF2 in cryogenic matrixes. Combined with the results from infrared spectroscopy and density functional theory calculations, the sulfur ligand in M(O)(S)F2 is characterized to be a terminally bound radical with the unpaired electron located on the sulfur 3p orbital. Besides this radical complex, calculations also predict the existence of MF2(η2-SO) with a side-on SO ligand, but this less stable isomer is not observed as a result of high exothermicity along with its formation from metal atoms and SOF2 that is large enough to overcome the energy barrier towards the occurrence of M(O)(S)F2.
Rapid and column-free syntheses of acyl fluorides and peptides usingex situgenerated thionyl fluoride
Lee, Cayo,Sammis, Glenn M.,Thomson, Brodie J.
, p. 188 - 194 (2021/12/31)
Thionyl fluoride (SOF2) was first isolated in 1896, but there have been less than 10 subsequent reports of its use as a reagent for organic synthesis. This is partly due to a lack of facile, lab-scale methods for its generation. Herein we report a novel protocol for theex situgeneration of SOF2and subsequent demonstration of its ability to access both aliphatic and aromatic acyl fluorides in 55-98% isolated yields under mild conditions and short reaction times. We further demonstrate its aptitude in amino acid couplings, with a one-pot, column-free strategy that affords the corresponding dipeptides in 65-97% isolated yields with minimal to no epimerization. The broad scope allows for a wide range of protecting groups and both natural and unnatural amino acids. Finally, we demonstrated that this new method can be used in sequential liquid phase peptide synthesis (LPPS) to afford tri-, tetra-, penta-, and decapeptides in 14-88% yields without the need for column chromatography. We also demonstrated that this new method is amenable to solid phase peptide synthesis (SPPS), affording di- and pentapeptides in 80-98% yields.
Multidimensional SuFEx Click Chemistry: Sequential Sulfur(VI) Fluoride Exchange Connections of Diverse Modules Launched From An SOF4 Hub
Li, Suhua,Wu, Peng,Moses, John E.,Sharpless, K. Barry
supporting information, p. 2903 - 2908 (2017/03/13)
Sulfur(VI) fluoride exchange (SuFEx) is a new family of click chemistry based transformations that enable the synthesis of covalently linked modules via SVI hubs. Here we report thionyl tetrafluoride (SOF4) as the first multidimensional SuFEx connector. SOF4 sits between the commercially mass-produced gases SF6 and SO2F2, and like them, is readily synthesized on scale. Under SuFEx catalysis conditions, SOF4 reliably seeks out primary amino groups [R-NH2] and becomes permanently anchored via a tetrahedral iminosulfur(VI) link: R?N=(O=)S(F)2. The pendant, prochiral difluoride groups R?N=(O=)SF2, in turn, offer two further SuFExable handles, which can be sequentially exchanged to create 3-dimensional covalent departure vectors from the tetrahedral sulfur(VI) hub.
