Diastereoselective Access to Polyoxygenated Polycyclic Spirolactones through a Rhodium-Catalyzed [3+2] Cycloaddition Reaction: Experimental and Theoretical Studies
作者:Fabien Rodier、Michel Rajzmann、Jean-Luc Parrain、Gaëlle Chouraqui、Laurent Commeiras
DOI:10.1002/chem.201203155
日期:2013.2.11
utility of γ‐alkylidenebutenolides is demonstrated as highly competent dipolarophile partners in both intra‐ and intermolecular rhodium(II)‐catalyzed 1,3‐dipolar cycloaddition reactions. The strength of this approach lies in the formation of spiro[6,4]lactone moieties with the concomitant construction of quaternary spiro stereocenters. Typically, the construction of spirolactones involves an esterification
γ-亚烷基丁烯内酯的合成实用性在分子内和分子间铑(II)催化的1,3-偶极环加成反应中均被证明是高效的偶极亲和性伴侣。这种方法的优势在于形成螺[6,4]内酯部分,并伴随着四价螺立体中心的构建。通常,螺内酯的构建涉及酯化步骤,该步骤经常被报道为“生物合成途径”,并且通常在总合成的最后步骤或接近最终步骤的情况下发生。此外,据报道,从五味子中分离出的分子的(5,7)骨架形成了一条聚合的通用路径。属。进行了计算研究,以全面了解2-重氮-1,3-酮酸酯和原香豆素之间的分子间[3 + 2]环加成的机理,并使经验观察合理化。特别是,我们首次证明,铑中心在环化步骤本身中起着重要作用,并与亲双亲体以叶立德络合物的形式发生反应。