A Convergent Pd-Catalyzed Asymmetric Allylic Alkylation ofdl- andmeso-Divinylethylene Carbonate: Enantioselective Synthesis of (+)-Australine Hydrochloride and Formal Synthesis of Isoaltholactone
作者:Barry M. Trost、Aaron Aponick、Benjamin N. Stanzl
DOI:10.1002/chem.200700832
日期:2007.11.26
The use of a mixture of dl- and meso-divinylethylene carbonate as an electrophile in palladium-catalyzed asymmetric allylic alkylation reactions is reported. From the diastereomeric mixture of meso and chiral racemic starting materials, a single product is obtained in high optical purity employing either oxygen or nitrogen nucleophiles. The resulting dienes have proven to be versatile synthetic intermediates
据报道,在钯催化的不对称烯丙基烷基化反应中,使用碳酸dl-和间-二乙烯基碳酸亚乙酯的混合物作为亲电子试剂。从内消旋和手性外消旋起始材料的非对映异构体混合物中,使用氧或氮亲核试剂可得到高光学纯度的单一产物。事实证明,生成的二烯是通用的合成中间体,因为每个碳都经过官能化以进一步转化,并通过反应进行区分。提出了这种令人感兴趣的转化的机制,并且报道了简明的(+)-澳式碱性盐酸盐的对映选择性全合成以及异甲内酯的正式合成。