Shintani Ryo, Park Soyoung, Hayashi Tamio
Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502, Japan.
J Am Chem Soc. 2007 Dec 5;129(48):14866-7. doi: 10.1021/ja077236o. Epub 2007 Nov 10.
A palladium-catalyzed intermolecular cycloaddition of gamma-methylidene-delta-valerolactones with electron-deficient olefins has been developed for the synthesis of spiro[2.4]heptanes with high selectivity through a nucleophilic ring closure to the central carbon of a pi-allylpalladium intermediate. It was found that the course of the reaction is dependent on the ligand employed, and selective [4 + 2] cycloadditions can also be achieved by the use of a bulky monophosphine ligand.
已开发出一种钯催化的γ-亚甲基-δ-戊内酯与缺电子烯烃的分子间环加成反应，通过亲核环合到π-烯丙基钯中间体的中心碳上，以高选择性合成螺[2.4]庚烷。发现反应过程取决于所使用的配体，并且通过使用大位阻单膦配体也可以实现选择性的[4 + 2]环加成反应。
