AbstractStereoselective Zweifel olefination using boronate complexes carrying two different reactive π‐systems was achieved to synthesize vinyl heteroarenes and conjugated 1,3‐dienes in good yield and up to 100 % stereoselectivity, which remains unexplored until now. Most importantly, we report the unprecedented formation of E vs. Z‐vinyl heteroarenes for different heteroarenes under identical conditions. Density functional theory (DFT) investigations unveil the mechanistic dichotomy between olefin and heteroarene activation followed by 1,2‐migration, leading to E or Z‐vinyl heteroarenes respectively. We also report a previously unknown reversal of stereoselectivity by using 2,3‐Dichloro‐5,6‐dicyano‐1,4‐benzoquinone (DDQ) as an electrophile. The Zweifel olefination using a boronate complex that carries two different olefins was previously unexplored due to significant challenges associated with the site‐selective activation of olefins. We have solved this problem and reported the site‐selective activation of olefins for the stereoselective synthesis of 1,3‐dienes.
摘要利用携带两种不同反应性 π-系统的硼酸盐配合物实现了全选择性 Zweifel 烯化反应,从而以良好的收率和高达 100 % 的立体选择性合成了乙烯基杂环戊烯和共轭 1,3 二烯,这一点迄今为止仍未得到探索。最重要的是,我们报告了在相同条件下不同杂环戊烯与 Z-乙烯基杂环戊烯前所未有的形成过程。密度泛函理论(DFT)研究揭示了烯烃和杂环戊烯活化后 1,2 迁移分别导致 E 或 Z 乙烯基杂环戊烯的机理二分法。我们还报告了通过使用 2,3-二氯-5,6-二氰基-1,4-苯醌(DDQ)作为亲电子体,实现了一种之前未知的立体选择性逆转。由于烯烃的位点选择性活化存在巨大挑战,使用携带两种不同烯烃的硼酸酯复合物进行 Zweifel 烯化反应的研究以前从未进行过。我们已经解决了这一问题,并报告了用于立体选择性合成 1,3 二烯的烯烃位点选择性活化。