Stereoselective Dehydroxyboration of Allylic Alcohols to Access (<i>E</i>)-Allylboronates by a Combination of C–OH Cleavage and Boron Transfer under Iron Catalysis
Iron-catalyzed direct SN2′ dehydroxyboration of allylic alcohols has been developed to access (E)-stereoselective allylboronates. Allylic alcohols with diverse structures and functional groups, especially derived from natural products, underwent smooth transformation. The six-membered ring transition state formed by allylic alcohols and iron–boron intermediate was indicated to be the key component
铁催化的烯丙醇直接 S N 2' 脱羟基硼酸已被开发用于获得 ( E )-立体选择性烯丙基硼酸酯。具有多种结构和官能团的烯丙醇,特别是来自天然产物的烯丙醇,经历了平稳的转变。由烯丙醇和铁-硼中间体形成的六元环过渡态被证明是参与硼基团转移、C-OH键活化和立体选择性控制的关键成分。
作者:Y. Tamaru、Y. Yamada、H. Ochiai、E. Nakajo、Z. Yoshida
DOI:10.1016/s0040-4020(01)91131-7
日期:1984.1
Diastereomeric mixtures of 2-substituted 1-vinyclyclohexyl acetates (or benzoates) are rearranged stereoselectively to 2-substituted (E)-β-acetoxy(or benzoyloxy)ethylidenecyclohexanes by the catalysis of bis(acetonitrile)palladium(II) chloride. A mechanism related to the stereoselectivity and reactivity is discussed in terms of the conformational requirements in a transition state.