N-(4-Chlorophenylthio) -3,5-di-t-butylphenylaminyl was decomposed in oxygen-free benzene, and the products were examined. On the basis of the results, the decomposition mechanism of the radical is described.
Catalytic formal [2+2+1] synthesis of pyrroles from alkynes and diazenes via TiII/TiIV redox catalysis
作者:Zachary W. Gilbert、Ryan J. Hue、Ian A. Tonks
DOI:10.1038/nchem.2386
日期:2016.1
Pyrroles are structurally important heterocycles. However, the synthesis of polysubstitutedpyrroles is often challenging. Here, we report a multicomponent, Ti-catalysed formal [2+2+1] reaction of alkynes and diazenes for the oxidative synthesis of penta- and trisubstituted pyrroles: a nitrenoid analogue to classical Pauson–Khand-type syntheses of cyclopentenones. Given the scarcity of early transition-metal
吡咯是结构上重要的杂环。然而,多取代的吡咯的合成通常具有挑战性。在这里,我们报道了炔烃和二烯的多组分,钛催化的正式[2 + 2 + 1]反应,用于五和三取代吡咯的氧化合成:类似于经典的Pauson-Khand型环戊烯酮合成的亚硝基类似物。鉴于早期过渡金属氧化还原催化的稀缺性,提出了初步的机理研究。最初的化学计量和动力学研究表明,该反应的机理是通过正式的Ti II / Ti IV进行的氧化还原催化循环,其中由[2 + 2]炔烃+ Ti亚氨基偶合反应生成的氮杂环丁烷环丁烯中间体经历第二次炔烃插入,然后还原消除,得到吡咯和Ti II物质。催化转换的关键成分是通过η2-二氮杂苯-Ti II络合物的歧化将Ti II物种再氧化为Ti IV酰亚胺基。
London Dispersion in Alkane Solvents
作者:Marcel A. Strauss、Hermann A. Wegner
DOI:10.1002/anie.202012094
日期:2021.1.11
The importance of Londondispersion interactions in solution is an ongoing debate. Although the significance of dispersion for structure and stability is widely accepted, the degree of its attenuation in solution is still not properly understood. Quantitative evaluations are derived mostly from computations. Experimental data provide guidelines to include Londondispersion in solution phase design. Herein