Hydroboration. 93. Convenient Conversion of Optically Pure 2-Organylapopinenes into the (2-Organylapoisopinyl)dihaloboranes Potentially Valuable for Asymmetric Synthesis via Chiral Organoboranes
作者:Ulhas P. Dhokte、Herbert C. Brown
DOI:10.1021/om960240g
日期:1996.8.6
Optically pure and sterically varied (2-organylapoisopinyl)dihaloboranes [RapBX2, R = Me (except for X = I), Et, Pr, i-Bu, Ph, i-Pr, X = Cl, Br, I], potentially important reagents for asymmetric synthesis, are conveniently prepared by the in situ reduction and hydroboration reaction of boron trihalide, trimethylsilane, and 2-organylapopinenes (2-R-apopinenes) under mild reaction conditions in essentially
可能是光学纯且呈空间变化的(2-organylapoisopinyl)二卤环烷酮[RapBX 2,R = Me(X = I除外),Et,Pr,i -Bu,Ph,i -Pr,X = Cl,Br,I],不对称合成的重要试剂可通过在温和的反应条件下原位还原三卤化硼硼,三甲基硅烷和2-有机基罂粟碱(2-R-罂粟碱)并进行硼氢化反应来制备,其定量产率基本可得。不幸的是,尽管更大体积的2-R-罂粟碱提供了所需的RapBI 2衍生物,但是不能通过该方法合成IpcBI 2(RapBI 2,R = Me)。