Pinheiro Danielle L J, Batista Gabriel M F, de Castro Pedro P, Flores Leonã S, Andrade Gustavo F S, Amarante Giovanni W
Chemistry Department, Federal University of Juiz de Fora, Cidade Universitária, São Pedro, Juiz de Fora, MG, CEP 36036-900, Brazil.
Beilstein J Org Chem. 2017 Dec 13;13:2663-2670. doi: 10.3762/bjoc.13.264. eCollection 2017.
A novel Brønsted base system for the diastereoselective dimerization of azlactones using trichloroacetate salts and acetonitrile has been developed. Desired products were obtained in good yields (60-93%) and with up to >19:1 dr after one hour of reaction. Additionally, the relative stereochemistry of the major dimer was assigned as being , by X-ray crystallographic analysis. The kinetic reaction profile was determined by using H NMR reaction monitoring and revealed a second order overall kinetic profile. Furthermore, by employing this methodology, a diastereoselective total synthesis of a functionalized analogue of streptopyrrolidine was accomplished in 65% overall yield.
已开发出一种新型布朗斯特碱体系,用于使用三氯乙酸盐和乙腈对恶唑酮进行非对映选择性二聚反应。反应一小时后,所需产物以良好的产率(60 - 93%)得到,非对映选择性高达>19:1。此外,通过X射线晶体学分析确定主要二聚体的相对立体化学结构为 。通过使用1H NMR反应监测确定了动力学反应曲线,结果显示为二级整体动力学曲线。此外,采用这种方法,以65%的总产率完成了链霉吡咯烷功能化类似物的非对映选择性全合成。