200639-98-1Relevant academic research and scientific papers
First detection of a selenenyl fluoride ArSe-F by NMR spectroscopy: The nature of Ar2Se2/XeF2 and ArSe-SiMe 3/XeF2 reagents
Poleschner, Helmut,Seppelt, Konrad
, p. 6565 - 6574 (2007/10/03)
Arylselenenyl fluorides ArSeF are obtained from diselenides Ar 2Se2 or arylselenotrimethylsilanes ArSe-SiMe3, and XeF2. They are detected by low-temperature 19F and 77Se NMR spectroscopy. Substitution in the ortho position of the aromatic ring to provide electronic or steric protection is a requirement for their formation. ArSe-F compounds decompose according to 3 ArSe-F → [ArSe-SeF2Ar] + ArSe-F- → ArSeF3 + Ar 2Se2. Reaction energies for this disproportionation as well as that of the sulfur and tellurium homologues have been calculated with MP2, CCSD(T,) and B3 LYP methods. They were found to be increasingly exothermic in the sequence S 77Se and 19F chemical shifts have been calculated by GIAO-MP2 and GIAO-B3LYP methods and are in good agreement with experimental values.
Asymmetric addition reactions with optimized selenium electrophiles
Wirth, Thomas,Fragale, Gianfranco
, p. 1894 - 1902 (2007/10/03)
The synthesis of various nonracemic diselenides by different methods is described. These diselenides are precursors for optically active selenium electrophiles. Their facial selectivity upon addition to styrene was investigated with respect to the chiral moiety neighboring the selenium. Diselenides 1i, 1n, and 1v yielded addition products 7 with diastereomeric excesses up to 95%. Some diselenides, intermediates, and products of the addition reaction were investigated by 77Se NMR spectroscopy.
