Recognition-encoded melamine oligomers (REMO) are synthetic polymers that feature an alternating 1,3,5-triazine-piperazine backbone and side-chains equipped with either a phenol or phosphine oxide recognition unit. An automated method for the solid-phase synthesis (SPS) of REMO of any specified sequence has been developed starting from dichlorotriazine monomer building blocks. Complementary homo-oligomers with either six phenols or six phosphine oxides were synthesized and shown to form a stable duplex in nonpolar solvents by NMR denaturation experiments. The duplex was covalently trapped by equipping the ends of the oligomers with an azide and an alkyne group and using a copper-catalyzed alkyne–azide cycloaddition (CuAAC) reaction. The SPS methodology was adapted to synthesize mixed sequence libraries by using a mixture of two different dichlorotriazine building blocks in each coupling cycle of an oligomer synthesis. The resulting libraries contain statistical mixtures of all possible sequences. The self-assembly properties of these libraries were screened by using the CuAAC reaction to trap any duplexes present. In mixed sequence libraries of 6-mers, the trapping experiments showed that only sequence-complementary oligomers formed duplexes at micromolar concentrations in dichloromethane. The automated synthesis approach developed here provides access to large libraries of mixed sequence synthetic polymers, and the covalent trapping experiment provides a convenient tool for screening functional properties of mixtures. The results suggest high-fidelity sequence-selective duplex formation in mixtures of 6-mer sequences of the REMO architecture.

中文翻译：

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合成聚合物混合序列库中的选择性双链体形成

识别编码三聚氰胺低聚物 (REMO) 是一种合成聚合物，具有交替的 1,3,5-三嗪-哌嗪主链和配备有苯酚或氧化膦识别单元的侧链。从二氯三嗪单体构建块开始，开发了一种用于任意指定序列的 REMO 固相合成 (SPS) 的自动化方法。合成了具有六种酚或六种氧化膦的互补均聚低聚物，并通过 NMR 变性实验证明其在非极性溶剂中形成稳定的双链体。通过在低聚物的末端配备叠氮基和炔基并使用铜催化的炔-叠氮环加成（CuAAC）反应，双链体被共价捕获。 SPS 方法适用于通过在寡聚物合成的每个偶联循环中使用两种不同的二氯三嗪结构单元的混合物来合成混合序列文库。所得文库包含所有可能序列的统计混合物。通过使用 CuAAC 反应捕获任何存在的双链体来筛选这些文库的自组装特性。在 6 聚体的混合序列文库中，捕获实验表明，只有序列互补的寡聚物在二氯甲烷中以微摩尔浓度形成双链体。这里开发的自动化合成方法提供了对混合序列合成聚合物的大型库的访问，共价捕获实验提供了筛选混合物功能特性的便捷工具。结果表明 REMO 架构的 6 聚体序列混合物中形成高保真序列选择性双链体。