Laboratory of Chemistry and Bioengineering, Tampere University of Technology , Korkeakoulunkatu 8, 33101 Tampere, Finland.
Instituto de Investigação do Medicamento (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa , Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal.
J Org Chem. 2018 Feb 16;83(4):1948-1958. doi: 10.1021/acs.joc.7b02896. Epub 2018 Jan 26.
The autoxidative condensation of 2-aryl-2-lithio-1,3-dithianes is here reported. Treatment of 2-aryl-1,3-dithianes with n-BuLi in the absence of any electrophile leads to condensation of three molecules of 1,3-dithianes and formation of highly functionalized α-thioether ketones orthothioesters in 51-89% yields upon air exposure. The method was further expanded to benzaldehyde dithioacetals, affording corresponding orthothioesters and α-thioether ketones in 48-97% yields. The experimental results combined with density functional theory studies support a mechanism triggered by the autoxidation of 2-aryl-2-lithio-1,3-dithianes to yield a highly reactive thioester that undergoes condensation with two other molecules of 2-aryl-2-lithio-1,3-dithiane.
本文报道了 2-芳基-2-锂-1,3-二硫杂环戊烷的自氧化缩合反应。在不存在任何亲电试剂的情况下，用正丁基锂处理 1,3-二硫杂环戊烷，会导致三个分子的 1,3-二硫杂环戊烷缩合，并在暴露于空气中时以 51-89%的收率生成高度官能化的α-硫醚酮砜。该方法进一步扩展到苯甲醛二硫缩醛，以 48-97%的收率得到相应的砜和α-硫醚酮。实验结果与密度泛函理论研究相结合，支持了一种由 2-芳基-2-锂-1,3-二硫杂环戊烷的自氧化引发的机制，生成一种高反应性的硫代酯，它与另外两个分子的 2-芳基-2-锂-1,3-二硫杂环戊烷发生缩合反应。
