An Unexpected Michael-Aldol-Smiles Rearrangement Sequence for the Synthesis of Versatile Optically Active Bicyclic Structures by Using Asymmetric Organocatalysis
作者:Nicole Holub、Hao Jiang、Marcio W. Paixão、Caterina Tiberi、Karl A. Jørgensen
DOI:10.1002/chem.200903274
日期:2010.4.12
A facile and simple organocatalytic procedure to generate optically active 6‐alkyl‐ and 6‐aryl‐substituted bicyclo[2.2.2]oct‐5‐en‐2‐ones is presented. The reaction is catalysed by a 9‐amino‐9‐deoxyepiquinine trifluoroacetic acid salt, which activates α,β‐unsaturated cyclic ketones for the 1,4‐addition of β‐keto benzothiazoyl sulfones in a stereoselective fashion. Subsequent intramolecular aldol reaction
提出了一种简便而简单的有机催化程序,可生成光学活性的6-烷基和6-芳基取代的双环[2.2.2] oct-5-en-2-ones。该反应由9-氨基-9-脱氧表醌三氟乙酸盐催化,该盐以立体选择性的方式激活α,β-不饱和环酮,以1,4-加成β-酮基苯并噻唑基砜。随后的分子内醛醇缩合反应和Smiles重排产生了重要的光学活性自行车,这些自行车是天然产物,不对称催化的配体以及应付重排,光化学反应,自由基环化和复分解反应的底物的常见基序。利用各种环状烯酮或进行扩环反应可获得不同的双环结构。此外,