The Choice of Phosphane Reagent in Fukuyama−Mitsunobu Alkylation: Intramolecular Selectivity Between Primary and Secondary Alcohols in the Preparation of Asymmetric Tetraamine Building Blocks for Synthesis of Philanthotoxins
作者:Christian A. Olsen、Malene R. Jørgensen、Matthias Witt、Ian R. Mellor、Peter N. R. Usherwood、Jerzy W. Jaroszewski、Henrik Franzyk
DOI:10.1002/ejoc.200300186
日期:2003.9
phosphane reagent more bulky than trimethylphosphane gave a high intramolecular selectivity between primary and secondary hydroxy groups in the Fukuyama−Mitsunobu reaction. Thus, trimethylphosphane proved to be the only phosphane reagent that enabled alkylation of 2-nitrobenzenesulfonamides with a wide range of secondary alcohols, whereas tributylphosphane was selective for primary alcohol groups. This
Philanthotoxin-433 (PhTX-433) 是一种多胺黄蜂毒素,可非竞争性地拮抗某些离子型受体。PhTX-433 的四个类似物,在多胺链中被 C-甲基化,由 (RS)-1,3-丁二醇、两个二胺结构单元和一个活化/保护的酪氨酸衍生物合成。在 Fukuyama-Mitsunobu 反应中,使用比三甲基磷烷体积更大的磷烷试剂在伯羟基和仲羟基之间具有高分子内选择性。因此,三甲基磷烷被证明是唯一能够使 2-硝基苯磺酰胺与多种仲醇烷基化的磷烷试剂,而三丁基磷烷对伯醇基团具有选择性。这种选择性被用来获得正交保护的、不对称的、支化的四胺,用于 philanthotoxin 类似物的液相合成。使用在非洲爪蟾卵母细胞中表达的大鼠脑离子型谷氨酸受体在电生理学测定中测试由此获得的分支的philanthotoxin类似物。事实证明,它们的效力与相应的非分支类似物相似。(© Wiley-VCH Verlag