All-Catalytic, Efficient, and Asymmetric Synthesis of α,ω-Diheterofunctional Reduced Polypropionates via “One-Pot” Zr-Catalyzed Asymmetric Carboalumination−Pd-Catalyzed Cross-Coupling Tandem Process
作者:Tibor Novak、Ze Tan、Bo Liang、Ei-ichi Negishi
DOI:10.1021/ja043534z
日期:2005.3.9
A highly efficient method for the synthesis of stereochemically pure (>/=99% ee and >50/1 dr) alpha,omega-diheterofunctional reduced polypropionates has been developed. The essential features of the method are represented by the conversion of inexpensive styrene into 2-methyl-4-phenyl-1-pentanol (1) in 50% yield over two steps from styrene via Zr-catalyzed asymmetric carboalumination (ZACA) reaction
已开发出一种用于合成立体化学纯 (>/=99% ee 和 >50/1 dr) 的 alpha,omega-diheterofunctional 还原聚丙酸酯的高效方法。该方法的基本特征是通过 Zr 催化的不对称碳铝化 (ZACA) 反应将廉价的苯乙烯转化为 2-甲基-4-苯基-1-戊醇 (1),分两步以 50% 的收率将苯乙烯转化为(NMI)2ZrCl2 的存在和在 Zn(OTf)2 和催化量的 Pd(DPEphos)Cl2 存在下原位生成的异烷基丙烷的 Pd 催化乙烯基化。这种ZACA-Pd催化的乙烯基化可以根据需要重复进行而无需纯化。在最终的 ZACA 反应之后,用 O2 氧化得到 α-羟基-ω-苯基还原的聚丙酸酯,可以通过色谱完全或部分纯化。乙酰化后,