Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, São Paulo, Brazil.
Beilstein J Org Chem. 2008 Feb 5;4:9. doi: 10.1186/1860-5397-4-9.
Through direct transmetalation reaction of Z-vinylic tellurides with nBuLi was observed the unexpected isomerization of double bonds leading to potassium E-vinyltrifluoroborates salts in low to moderate yields. Using EPR spin trapping experiments the radical species that promoted the stereoinversion of Z-vinylic organometallic species during the preparation of potassium vinyltrifluoroborate salts was identified. The experiments support the proposed mechanism, which is based on the homolytic cleavage of the TenBu bond.
通过 Z-烯丙基碲化物与正丁基锂的直接转金属反应，观察到双键的意外异构化，导致钾 E-乙烯三氟硼酸盐盐以低至中等产率生成。通过 EPR 自旋捕获实验，确定了在制备钾乙烯三氟硼酸盐盐过程中促进 Z-烯丙基有机金属物种立体反转的自由基物种。实验支持了所提出的基于 TenBu 键均裂的机制。
