C2-Symmetric hemiaminal ethers and diamines: new ligands for copper-catalyzed desymmetrization of meso-1,2-diols and asymmetric Henry reactions
作者:Zbigniew Kałuża、Krzysztof Bielawski、Rafał Ćwiek、Piotr Niedziejko、Przemysław Kaliski
DOI:10.1016/j.tetasy.2013.09.011
日期:2013.11
The synthesis of novel, enantiomerically pure C2-symmetrical hemiaminal ethers and diamines containing piperazine core is presented. The key steps of the synthesis involve the dimerization of an in situ generated α-amino aldehyde into the corresponding cyclic bis-hemiaminal, followed by dehydration in the presence of a base to give a 7-oxa-2,5-diaza-bicyclo[2.2.1]heptane derivative, which can be regarded
提出了新颖的,对映体纯的含哌嗪核心的对映体纯的C 2对称半氨基醚和二胺的合成。合成的关键步骤包括将原位生成的α-氨基醛二聚为相应的环状双半缩醛,然后在碱存在下脱水,得到7-oxa-2,5-diaza-bicyclo [ 2.2.1]庚烷衍生物,可以视为双环双半缩醛内醚。这些化合物代表了一类新的分子,首次明确地建立了结构。最后,三乙酰氧基-硼氢化钠还原得到相应的二胺。这两类化合物,即新的二胺和半氨基醚,均被证明是铜(II)催化的内消旋对称化的良好配体。-二醇(高达87%ee)和亨利反应(高达84%ee)。