Intramolecular Pd-Catalyzed Carboetherification and Carboamination. Influence of Catalyst Structure on Reaction Mechanism and Product Stereochemistry
作者:Josephine S. Nakhla、Jeff W. Kampf、John P. Wolfe
DOI:10.1021/ja057489m
日期:2006.3.1
is likely due to a change in reaction mechanism. Evidence is presented that suggests the syn-addition products derive from an unprecedented transannular alkene insertion of an 11-membered Pd(Ar)(OR) complex. In contrast, the anti-addition products appear to arise from Wacker-type anti-oxypalladation. Studies on analogous Pd-catalyzed intramolecular carboamination reactions, which afford 2-indan-1-ylpyrrolidines
烯烃的分子内 Pd 催化的碳醚化以中等至良好的收率提供 2-indan-1-yltetrahydrofuran 产物,并具有良好至极好的非对映选择性。这些反应的立体化学结果取决于 Pd 催化剂的结构。使用 PCy(3) 或 P[(4-MeO)C(6)H(4)](3) 作为 Pd 的配体导致芳烃和氧原子跨双键的顺式加成,而使用(+/-)-BINAP 或 DPP-苯提供由反加成产生的产物。催化剂引起的立体化学变化可能是由于反应机制的变化。有证据表明,syn-加成产物源自前所未有的跨环烯烃插入的 11 元 Pd(Ar)(OR) 配合物。相比之下,反加成产物似乎来自瓦克型反氧化钯。还描述了对类似 Pd 催化的分子内碳胺化反应的研究,该反应提供了由顺式加成产生的 2-indan-1-ylpyrrolidines。