Department of Chemistry, Sungkyunkwan University , Suwon 440-746, Korea.
Western Seoul Center, Korea Basic Science Institute , Seoul 120-140, Korea.
Org Lett. 2016 Jan 15;18(2):160-3. doi: 10.1021/acs.orglett.5b02970. Epub 2015 Dec 31.
Chiral oxazaborolidinium ion-catalyzed asymmetric cyclopropanation of α- or α,β-substituted acroleins with α-alkyl-α-diazoesters has been developed. With this methodology, chiral functionalized cyclopropanes containing a quaternary stereogenic center were obtained with high to excellent enantioselectivities (up to >99% ee). The synthetic utility of optically enriched functionalized cyclopropane was demonstrated in the first total synthesis of (+)-hamavellone B, which establishes the absolute configuration of natural (+)-hamavellone B.
手性恶唑硼烷离子催化的 α-或 α,β-取代丙烯醛与 α-烷基-α-重氮酯的不对称环丙烷化反应已经被开发出来。使用这种方法，可以高对映选择性（高达 >99%ee）得到含有季立体中心的手性官能化环丙烷。在 (+)-hamavellone B 的首次全合成中，展示了光学纯官能化环丙烷的合成实用性，该全合成确定了天然 (+)-hamavellone B 的绝对构型。
