Trost Barry M, Quancard Jean
Department of Chemistry, Stanford University, Stanford, California 94305-5080, USA.
J Am Chem Soc. 2006 May 17;128(19):6314-5. doi: 10.1021/ja0608139.
We have developed a new enantioselective C-3 allylation of 3-substituted indoles using allyl alcohol and trialkylboranes. Asymmetric syntheses of 3,3-disubstituted indolines and indolenines in enantiomeric excesses up to 90% have been achieved using the bulky borane 9-BBN-C6H13 as the promoter of the reaction. The dependence of the selectivity on the nature of the borane suggests that the boron reagent has a role beyond promoting ionization of the allyl alcohol. A protocol for oxidation of indolenines to oxindoles has also been developed and led to a formal synthesis of (-)-phenserine.
我们利用烯丙醇和三烷基硼烷开发了一种新的3-取代吲哚的对映选择性C-3烯丙基化反应。使用体积较大的硼烷9-BBN-C6H13作为反应促进剂，已实现对映体过量高达90%的3,3-二取代二氢吲哚和吲哚啉的不对称合成。选择性对硼烷性质的依赖性表明，硼试剂的作用不仅仅是促进烯丙醇的离子化。还开发了一种将吲哚啉氧化为羟吲哚的方法，并由此实现了(-)-苯丝氨酸的形式合成。
