Regioselective Synthesis of V‑Shaped Bistriazinyl-phenanthrolines

A new,
regioselective synthesis of V-shaped 2,9-bis­(6-(4-halophenyl)-1,2,4-triazin-3-yl)-1,10-phenanthrolines
(4XPhBTPhen) ligands was developed, creating access to a simple and
reliable synthesis of precursors for future supramolecular actinide
complexing systems. Described is a reactant-directed regioselective
synthetic method, which was found to be high yielding and reliable
and yields exclusively 6,6′-phenyl BTPhen derivatives (including
4-chloro and 4-bromo) in five simple steps. Molecular and crystal
structures of PhBTP and PhBTPhen products are fully determined and
both were found to be in space group C2/c. Additionally, molecular and crystal structures of Z and E isomers of 2-hydrazono-2-phenylacetaldehyde
oxime, a reagent in the synthetic route, reveal existence of strong
intramolecular N–H···O hydrogen bonding in the Z isomer explaining its lower solubility in water.

本研究开发了一种新型区域选择性合成策略，用于制备V形2,9-双(6-(4-卤代苯基)-1,2,4-三嗪-3-基)-1,10-菲咯啉（4XPhBTPhen）类配体，可为未来超分子锕系络合体系的前驱体提供简便可靠的合成路径。本文报道了一种反应物导向的区域选择性合成方法，该方法产率优异、稳定性可靠，仅需五步简单反应即可专一地得到6,6'-苯基BTPhen衍生物（包括4-氯取代与4-溴取代产物）。PhBTP与PhBTPhen产物的分子及晶体结构均得到完整表征，二者均属于空间群C2/c。此外，对本合成路线中所用试剂2-腙基-2-苯基乙醛肟的Z型与E型异构体的分子及晶体结构分析表明，Z型异构体中存在强分子内N–H···O氢键，这一现象可解释其水溶性较低的原因。