Tao Xin, Škoch Karel, Daniliuc Constantin G, Kehr Gerald, Erker Gerhard
Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster Corrensstraße 40 48149 Münster Germany
Chem Sci. 2019 Dec 18;11(6):1542-1548. doi: 10.1039/c9sc03870a.
The trimethylene-linked bis-allene reacts with Piers' borane [HB(CF)] by a hydroboration/allylboration sequence to generate the cyclization product . Its pyridine adduct was isolated and characterized by X-ray diffraction. Compound undergoes a typical frustrated Lewis pair 1,2-P/B alkene addition reaction with PPh to give the heterobicyclic bridged olefinic zwitterionic product . The tetramethylene-linked bis-allene and its phenylene annulated analogue react with HB(CF) to give the analogous seven-membered ring products under mild conditions. The cyclization product undergoes a series of sequential allylboration reactions with two equivalents of allene followed by ring-closure to give the four-component coupling product . It undergoes FLP addition to an exo-methylene group upon treatment with PPh. Compound is oxidatively converted to the boron-free alcohol.
三亚甲基连接的双丙二烯通过硼氢化/烯丙基硼化序列与皮尔斯硼烷[HB(CF)]反应生成环化产物。分离出其吡啶加合物并通过X射线衍射进行表征。化合物与PPh发生典型的受阻路易斯对1,2 - P/B烯烃加成反应，得到杂双环桥连烯烃两性离子产物。四亚甲基连接的双丙二烯及其亚苯基环化类似物在温和条件下与HB(CF)反应，得到类似的七元环产物。环化产物与两当量的丙二烯进行一系列连续的烯丙基硼化反应，然后闭环得到四组分偶联产物。用PPh处理时，它会对亚甲基进行FLP加成。化合物被氧化转化为无硼醇。
