Terminating catalytic asymmetric Heck cyclizations by stereoselective intramolecular capture of η3-allylpalladium intermediates: total synthesis of (−)-spirotryprostatin B and three stereoisomers
作者:Larry E. Overman、Mark D. Rosen
DOI:10.1016/j.tet.2010.05.048
日期:2010.8
A catalytic intramolecular Heck reaction, followed by capture of the resulting η3-allylpalladium intermediate by a tethered diketopiperazine, is the central step in a concise synthetic route to (−)-spirotryprostatin B and three stereoisomers. This study demonstrates that an acyclic, chiral η3-allylpalladium fragment generated in a catalytic asymmetric Heck cyclization can be trapped by even a weakly
催化分子内 Heck 反应,然后通过束缚的二酮哌嗪捕获所得的 η 3 -烯丙基钯中间体,是 (-)-螺环前列腺素 B 和三种立体异构体的简洁合成路线中的核心步骤。该研究表明,在催化不对称 Heck 环化中产生的无环手性 η 3 -烯丙基钯片段,即使是弱亲核性的二酮哌嗪也可以比非对映体平衡更快地捕获。