Trost Barry M, Aponick Aaron, Stanzl Benjamin N
Department of Chemistry, Stanford University, Stanford, CA 94305-5080, USA.
Chemistry. 2007;13(34):9547-60. doi: 10.1002/chem.200700832.
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 as each carbon is functionalized for further transformation and differentiated by virtue of the reaction. A mechanism for this intriguing transformation is proposed and a concise enantioselective total synthesis of (+)-australine hydrochloride is reported as well as a formal synthesis of isoaltholactone.
据报道，在钯催化的不对称烯丙基烷基化反应中，使用dl-和内消旋二乙烯基碳酸酯的混合物作为亲电试剂。从中性和手性外消旋起始原料的非对映体混合物中，使用氧或氮亲核试剂可获得高光学纯度的单一产物。所得二烯已被证明是通用的合成中间体，因为每个碳原子都经过官能团化以便进一步转化，并通过反应得以区分。本文提出了这种有趣转化的机理，还报道了(+)-澳洲茄碱盐酸盐的简洁对映选择性全合成以及异阿尔托内酯的形式合成。
