Bisphosphine-Functionalized Cyclic Decapeptides Based on the Natural Product Gramicidin S: A Potential Scaffold for Transition-Metal Coordination
作者:Sebastian Burck、Sander G. A. van Assema、Bas Lastdrager、J. Chris Slootweg、Andreas W. Ehlers、José M. Otero、Bruno Dacunha-Marinho、Antonio L. Llamas-Saiz、Mark Overhand、Mark J. van Raaij、Koop Lammertsma
DOI:10.1002/chem.200901127
日期:2009.8.17
The natural product Gramicidin S is a promising scaffold for novel oligopeptide‐based bisphosphine ligands, combining the advantageous rigid chiral backbone with the close proximity of phosphine substituents. The required unnatural, phosphine‐containing, amino acid building blocks were synthesized by means of a novel protocol that involves the enantioselective alkylation of a chiral nickel Schiff base
天然产物Gramicidin S是新型寡肽双膦配体的有前途的支架,将有利的刚性手性骨架与膦取代基紧密结合在一起。通过一种涉及手性镍席夫碱模板的对映选择性烷基化的新方案,合成了所需的非天然的,含膦的氨基酸构件。制备了三个Ni配合物,其中膦基和掺入的甘氨酸的α-碳原子之间具有不同的烷基链;其中两个的绝对立体化学是通过单晶X射线结构分析确定的。通过分离模板,对映体L膦氨基酸使固相,逐步构建膦修饰的寡肽的线性序列成为可能。在环化过程中,产生了三个双膦取代的Gramicidin S类似物,只是膦基和寡肽骨架之间的连接大小和形状不同。它们的晶体结构表明这些物质具有作为螯合配体的潜力。