作者:Angelo Alberti、Massimo Benaglia、Bianca F. Bonini、Gian Franco Pedulli
DOI:10.1039/f19888403347
日期:——
A wide variety of radicals has been added to three relatively stable thiocarbonyl compounds, namely thiobenzoyltriphenylsilane (TBTPS), 2,4,6-tri-t-butylthiobenzaldehyde (TBTBA), and tris(trimethylsilyl)ethan-ethial or trisylthioaldehyde (TSTA), in order to test their ability to act as radical scavengers and the possibility of using them as spin-trapping agents. Reactions with radicals centred at elements
各种各样的自由基已添加到三种相对稳定的硫代羰基化合物中,即硫代苯甲酰基三苯基硅烷(TBTPS),2,4,6-三叔丁基硫代苯甲醛(TBTBA)和三(三甲基甲硅烷基)乙乙氧基或三丁基硫醛(TSTA),为了测试它们充当自由基清除剂的能力以及将其用作自旋捕集剂的可能性。在所有情况下,与自由基集中在第IV至VI族元素上的反应在所有情况下均提供了持久的自旋加合物,其通过电子能谱法研究。尤其是,TBTPS加合物显示出良好的esr光谱,在大多数情况下,超精细图谱可明确鉴定所捕获的自由基。已经监测了某些TBTA和TSTA加合物的衰减,并确定了该过程的速率常数。分别为7和(1.9±0.5)×10 6 dm 3 mol –1 s –1。
Reactions between Grignard Reagents and Thiocarbonyl Compounds: A Revisitation
The radical anions from thiobenzophenone, thiobenzoyltriphenylsilane, and 3,5-di-tert-butylthiobenzoyltriphenylsilane were detected by EPR spectroscopy when these compounds were reacted with a number of Grignard reagents, RMgBr. The radical adducts resulting from addition of R-. radicals to the thiones were also detected. The formation of the radical anions indicates unambiguously the occurrence of a SET process which might be the initial stage of these reactions. In the case of tris(trimethylsilyl)ethanethial only the radical adducts were detected. The first reduction potentials of these thiones have also been measured in order to verify the feasibility of the SET process. In agreement with the EPR experiments, the calculated standard free energy changes suggest that electron transfer is possible in the first three cases and disfavored with the thioaldehyde.
[4+2]-cycloadditions of thiones with nitrosoalkenes: synthesis of derivatives of 4H-1,5,2-oxathiazine, a new heterocyclic system.
作者:Bianca F. Bonini、Elisabetta Foresti、Gaetano Maccagnani、Germana Mazzanti、Piera Sabatino、Paolo Zani
DOI:10.1016/s0040-4039(00)94799-3
日期:——
Barbaro, Gaetano; Battaglia, Arturo; Giorgianni, Patrizia, Journal of the Chemical Society. Perkin transactions I, 1986, p. 381 - 386