Less is More: A Shortcut for Anionocages Design Based on (RPO₃²⁻)‐Monourea Coordination

Abstract

Anionocages have been developed as a unique family of hydrogen bonded cages. However, strategies for constructing anionocages are mainly limited to that based on (PO 4 3À )-bisurea coordination, neither the ligands nor the anions lack the simplicity and diversity of the maturely developed analogues based on metal coordination (i.e. metallocage). We report herein a more simple strategy for anionocages design based on (RPO 3 2À )-monourea coordination, utilizing monourea rather than bisurea as the hydrogen binding donor, and RPO 3 2À rather than PO 4 3À

Stereoselective Assembly of Hydrogen‐Bonded Anionic Cages Dictated by Organophosphate‐Based Chiral Nodes

“…[20] In summary, we have developed an efficient strategy for the stereoselective synthesis of hydrogen-bonded cages, by . [10] In (c), the signal of H4 is partially overlapped by the Me signal of A 2R (◆). Enantioselectivity factors (K R /K S or K S /K R ) are shown as the insets.…”

“…To verify our design idea, TBA + (tetrabutylammonium) salts of phosphonomycin (antibiotics, A 1R ), (R/S)-tenofovir (antivirals, A 2R /A 2S ), adenosine monophosphate (natural product, AMP, A 3R ), and clindamycin phosphate (antibiotics, A 4R ) were selected to assemble with an achiral, bismonourea ligand L in MeCN (Scheme 1, please see Figures S1-S23 in Supporting Information for more details). [10] High-resolution ESI mass spectrometry (HRMS, Figures S24-S28) indicated that A 1R and A 2R /A 2S induced the formation of A 2 L 4 quadruple helicates (H 1R and H 2R / H 2S ), while A 3R and A 4R led to A 2 L 3 triple helicates (H 3R and H 4R ), which was attributed to the bulkiness of the chiral substituent group (R*) of A 3R and A 4R making an A 2 L 4 structure too crowded around the coordination center (Scheme 1, and Figure S29-S31). The 1 H NMR spectrum of each helicate showed one set of sharp signals, with the integral ratio of A : L consistent with that suggested by HRMS.…”

Anion‐Coordination‐Driven Assembly: From Discrete Supramolecular Self‐Assemblies to Functional Soft Materials

“…Two A 2 L 4 quadruple helicates, 18 4 (PhOPO 3 ) 2 and 18 4 (HOPO 3 ) 2 , were obtained by the self‐assembly of bis‐monourea ligand 18 and PhOPO 3 2− or HOPO 3 2− anions, respectively (Figure 8). [36] Crystal structures of 18 4 (PhOPO 3 ) 2 and 18 4 (HOPO 3 ) 2 showed that PhOPO 3 2− or HOPO 3 2− anions were coordinated with four monourea groups through a total of 8 hydrogen bonds. Especially, PhOPO 3 2− anion also interacted with naphthyl groups of ligand 18 by 7 short interactions to further enhance the stability and improve host‐guest combinations.…”

“…Two A 2 L 4 quadruple helicates, 18 4 (PhOPO 3 ) 2 and 18 4 (HOPO 3 ) 2 , were obtained by the selfassembly of bis-monourea ligand 18 and PhOPO 3 2À or HOPO 3 2À anions, respectively (Figure 8). [36] Crystal structures of 18 4 (PhOPO 3 ) 2 and 18 4 (HOPO 3 ) 2 showed that PhOPO 3 2À or HOPO 3 2À anions were coordinated with four monourea groups Figure 6. The crystal structures of M-15 3 (PO 4 ) 2 �R-G1, P-15 3 (PO 4 ) 2 �S-G1 and structures of choline and its derivatives, the chiral guest molecules.…”

Metallacages and Covalent Cages for Biological Imaging and Therapeutics

“…The majority of noncovalent cages are currently constructed through metal coordination, , anion coordination, , π–π stacking, and hydrogen bonds, among which metal coordination cages (abbreviated metallacages) are the most extensively studied. Saalfrank and co-workers reported the first metallacage in 1988, and since then, the groups of Fujita, Stang, Raymond, Nitschke, Shionoya, Clever, Yoshizawa, and others − have successfully developed various coordination-based self-assembly protocols to build numerous metallacages.…”