In this paper, the facile synthesis of hybrid Fe₃O₄ magnetic nanoparticles carrying helical poly(phenyl isocyanide) (PPI) arms via both “grafting from” and “grafting onto” strategies is reported. First, alkyne‐Pd(II) catalysts are anchored onto the surface of the Fe₃O₄ magnetic nanoparticle, which promote the polymerization of enantiopure phenyl isocyanide, affording the expected hybrid magnetic nanoparticle with Fe₃O₄ in core and helical PPI as arms. The nanoparticle also exhibits highly optical activity due to the excess of one‐handed helicity of the PPI arms. Moreover, the hybrid magnetic nanoparticle can be alternatively synthesized via “grafting onto” strategy. A triethoxysilanyl‐terminated single handed helical PPI bearing l‐alanine ester pendants is prepared and grafted onto the surface of Fe₃O₄ nanoparticle. The generated hybrid magnetic nanoparticles show both magnetic character and optical activity. Taking advantage of these properties, they can be used in enantioselective crystallization of racemic threonine. The enantiomeric excess (ee) of the induced crystals is up to 93%. Moreover, the nanoparticles can be facilely recovered and recycle used for at least four times in enantioselective crystallization without significantly loss of its enantioselectivity.

中文翻译：

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携带螺旋聚（苯基异氰化物）臂的光学活性和磁性纳米粒子的简便合成及其在对映选择性结晶中的应用

本文报道了通过“接枝”和“接枝”两种策略轻松合成带有螺旋聚（苯基异氰化物）（PPI）臂的杂化Fe ₃ O ₄磁性纳米粒子的方法。首先，将炔烃-Pd（II）催化剂固定在Fe ₃ O ₄磁性纳米粒子的表面上，从而促进对映纯苯基异氰酸酯的聚合，从而提供预期的与Fe ₃ O ₄混合的磁性纳米粒子。在核心和螺旋式PPI中作为武器。由于PPI臂的单手螺旋过多，因此纳米颗粒还具有很高的光学活性。此外，可以通过“嫁接到”策略来替代地合成杂化磁性纳米颗粒。制备带有l-丙氨酸酯侧基的三乙氧基硅烷基末端单手螺旋PPI，并将其接枝到Fe ₃ O ₄纳米颗粒的表面上。产生的杂化磁性纳米颗粒同时显示出磁性和光学活性。利用这些性质，它们可用于外消旋苏氨酸的对映选择性结晶。对映体过量（ee）的诱导晶体高达93％。而且，纳米颗粒可以容易地回收并循环至少四次用于对映选择性结晶，而不会显着损失其对映选择性。