Exploitation of high functional chiral building blocks by meso-asymmetrization using Ru^<II> catalyst.

本课题采用钌-手性胺配合物催化不对称氢转移反应制备手性KDP及其衍生物。首先，作者尝试了外消旋内烯丙醇催化不对称氢转移反应。催化不对称氢转移反应生成对映体富集的醇并生成非手性酮。因此，该反应损失了一半的起始物质，手性醇的产率最高可达50%。但在我的例子中，由于底物有合适的结构背景，就会得到手性烯酮和手性醇。实际上，手性烯丙醇和手性烯酮的最大ee分别为96%和54%。由于脂肪酶介导的动力学拆分方法不适用于外消旋α-取代内烯丙醇的动力学拆分，因此尝试通过催化不对称氢转移反应得到手性酮和手性烯丙醇。实际上，该反应提供了手性烯酮和手性烯丙醇的化学产率高且对映体过量，证明了不对称氢转移法是一种实用的分离KDP衍生物的方法。作者利用得到的手性化合物合成了具有生物活性的天然产物(+)-curcuphenol, (-)-pentenomycin I和(+)- arnicenone。

In this research project, the auther applied the catalytic asymmetric hydrogen transfer reaction using Ruthenium-chiral amine complex to obtain chiral KDP and its derivatives.First, the auther tried the catalytic asymmetric hydrogen transfer reaction of racemic endo-allyl alcohol.The catalytic asymmetric hydrogen transfer reaction proceeds to give enantiomerically enriched alcohols together with generation of achiral ketones.The reaction, therefore, loses one half of the starting material and the chiral alcohol will be obtained in maximum 50% yield. But in my case, as the substrate has an appropriate structural background, the chiral enone and the chiral alcohol will be obtained. In fact, the chiral allyl alcohol and the chiral enone were obtained in maximum 96% ee and 54% ee, respectively.As the lipase-mediated kinetic resolution was not useful method for kinetic resolution of the racemic α-substituted endo-allyl alcohols, the catalytic asymmetric hydrogen transfer reaction was tried to give chiral ketones and chiral allyl alcohols. The reaction, actually, provided the chiral enones and the chiral allyl alcohols in good chemical yields and also with high enantiomeric excess to prove the asymmetric hydrogen transfer method to be a practical method for the resolution of KDP derivatives .The auther utilized the obtained chiral compounds for the synthesis of the biological active natural products, (+)-curcuphenol, (-)-pentenomycin I and (+)- arnicenone.