Practical synthesis of pinacolborane for one-pot synthesis of unsymmetrical biaryls via aromatic C–H borylation–cross-coupling sequence
作者:Takao Kikuchi、Yusuke Nobuta、Junko Umeda、Yasunori Yamamoto、Tatsuo Ishiyama、Norio Miyaura
DOI:10.1016/j.tet.2008.03.102
日期:2008.5
A method for practical preparation of pinacolborane from borane-diethylaniline and pinacol was newly developed. Aromatic C–H borylation of arenes with pinacolborane or bis(pinacolato)diboron catalyzed by 1/2[Ir(OMe)(COD)]2-(4,4′-di-tert-butyl-2,2′-bipyridine) at 25 °C in hexane to give arylboronic esters was directly followed by cross-coupling with aromatic bromides at 60 °C in the presence of PdCl2(dppf)
新开发了一种由硼烷-二乙基苯胺和频哪醇实际制备频哪醇硼烷的方法。1/2 [Ir(OMe)(COD)] 2-(4,4'-二叔丁基-2,2'-联吡啶)催化的芳烃与频哪醇硼烷或双(频哪醇)二硼烷的芳烃C氢硼化在25℃下于己烷中在20℃下得到芳基硼酸酯,然后直接在60℃在PdCl 2(dppf)(3.0mol%)和K 3 PO 4在DMF中的存在下与芳族溴化物交叉偶联。这种一锅两步的方法以高收率提供了多种不对称的联芳基。