Cyclic BF<sub>2</sub> Adducts of Functionalized Fischer Vinylcarbene Complexes: Preparation and Stereoselective Diels−Alder Reactions with 2-Amino 1,3-Dienes
作者:José Barluenga、Rosa-María Canteli、Josefa Flórez、Santiago García-Granda、Angel Gutiérrez-Rodríguez、Eduardo Martín
DOI:10.1021/ja972588o
日期:1998.3.1
A new type of cyclic amino-functionalized s-cis boroxyvinylcarbene complex of group 6 metals has been synthesized. These complexes underwent Diels−Alder-type reactions with 2-amino 1,3-dienes that proceeded with complete regioselectivity and high exo or endo diastereoselectivity, which was found to be highly dependent on the nature of the substituents on the diene. When chiral 2-amino-5-alkoxy dienes
合成了一种新型的6族金属环状氨基官能化s-顺式硼氧基乙烯基卡宾配合物。这些配合物与 2-氨基 1,3-二烯进行 Diels-Alder 型反应,该反应具有完全的区域选择性和高外或内非对映选择性,这被发现高度依赖于二烯上取代基的性质。当使用衍生自 (S)-脯氨醇苄基或甲基醚的手性 2-氨基-5-烷氧基二烯时,实现了独特的外型和高度非对映选择性 [4 + 2] 环加成,提供具有三个连续立体中心和高水平的对映体纯度。去除 Cr(CO)5 片段和 BF2 基团提供了进入 α,α-支链 β-氨基醛或 β-氨基酸的途径。此外,