Synthesis of O6‐Corona[3]arene[3]pyridazines and Their Molecular Recognition Property in Organic and Aqueous Media

• Published in: Chinese journal of chemistry Vol. 36; no. 7; pp. 630 - 634
• Main Authors: Lu, Yao, Liang, Dong‐Dong, Fu, Zhan‐Da, Guo, Qing‐Hui, Wang, Mei‐Xiang
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY‐VCH Verlag GmbH & Co. KGaA 01.07.2018; Wiley Subscription Services, Inc
• Subjects: Acetic acid; Chemical synthesis; coronarene; Crystallography; Dihydroquinone; dinitrile; inverse electron demand Diels‐Alder reaction; Molecular chains; molecular recognition; O6‐coronaarenepyridazine; organic ammonium; Organic solvents; Pyridazines; Sodium; Sodium acetate; Water chemistry
• ISSN: 1001-604X; 1614-7065
• DOI: 10.1002/cjoc.201800131

O6‐Corona[3]arene[3]pyridazines were synthesized from the one‐pot macrocyclic condensation reaction of 3,6‐dichlorotetrazine with 1,4‐dihydroquinone derivatives followed by the inverse electron demand Diels‐Alder reaction of the tetrazine rings with a cyclopentanone‐derived enamine. Conversion of six ester groups within macrocycle into all sodium acetate moieties afforded a water soluble O6‐corona[3]arene[3]pyridazine. The coronary macrocycle host formed complexes selectively with organic ammoniums and dinitrile guests in a 1: 1 stoichiometric ratio in organic solvents with association constants ranging from (2.96 ± 0.10) × 101 to (2.53 ± 0.33) × 105 L·mol−1. Water soluble O6‐corona[3]arene[3]pyridazine was also able to complex strongly with organic ammoniums in water to give an association constant up to (2.67 ± 0.21) × 104 L·mol−1. The pseudo‐rotaxane and inclusion structures of the host‐guest complexes were revealed by the X‐ray crystallography. Lipophilic and hydrophilic O6‐corona[3]arene[3]pyridazines, which were synthesized from readily available O6‐corona[3]arene[3]tetrazines, acted as versatile and selective macrocyclic hosts to form complexes with ammonium guests in organic and aqueous media, respectively, with association constants ranging from (2.96 ± 0.10) × 101 to (2.53 ± 0.33) × 105 L·mol−1.