Supramolecular Architectures Incorporating Hydrogen‐Bonding Barbiturate Receptors

Abstract

An overview is presented of the representative members of the wide range of supramolecular host-guest complexes and polymers formed through the association of complementary hydrogen-bonding motifs comprising barbiturates (or structurally related cyanurates in specific cases) and Hamilton-type, bis(amidopyridine) receptor motifs, which offer strong selective binding in non-competitive media. A particular emphasis is placed on photoaddressable systems.Scheme 3. Hydrogen-bonding effector-mediated conformational reconstitution with a fused Hamilton-receptor oligomer (9). [18] Scheme 4. A linear supramolecular polymer from a hydrogen-bonded receptor (11) and a ditopic cyanurate (12). [19] Asian Scheme 7. Electronic energy transfer from a dansyl donor to a free-base porphyrin acceptor within a hydrogen-bonded scaffold. [30] Scheme 8. Self-assembled mixed monolayer (SAM) on a gold surface for fluorescence read-out of molecular recognition at a membrane-liquid interface. [32] Asian

Versatile control of the submolecular motion of di(acylamino)pyridine-based [2]rotaxanes

“…Nevertheless, the added value of DAP-based rotaxanes is the presence of a well-defined donor–acceptor–donor (D–A–D) hydrogen bond pattern. The molecular recognition 6 , 7 between the di(acylamino)pyridine subunit and complementary external binders restricts the amplitude of the ring motion in degenerate molecular shuttles. 5 The original translation can be restored through a competitive recognition event.…”

A new supramolecular bonding motif involving NH bonds of ammonium salts and macrocycles derived from platinum corners and butadiynediyl linkers

“…Supramolecular chemistry features two ubiquitous compositional elements that can come into play both independently and in concert: macrocyclic hosts and hydrogen bonding. 1 Some of the wide range of hydrogen bond donors and acceptors have biological roots 2 or are bio-inspired, 3 and others result from molecular design. 4,5 However, it is very unusual these days for new and effective hydrogen bonding partners to emerge “out of the blue”.…”

Mini-Review: Organic Catalysts in the 1,3-Dipolar Cycloaddition Reactions of Nitrile Oxides

“…The chiral transfer from a macrocyclic chiral receptor (host) to the appropriate substrate (guest) has been considered in the context of several asymmetric synthetic approaches. 33 In the case of the 1,3-DC of NOs some chiral macrocyclic barbiturate receptors 34 In these cases the expectation was that, upon host-guest binding, the orientation of the barbiturate conjugate in the chiral host will place the cinnamate moiety proximate to the chiral environment so that one face of the C=C double bond remains shielded. The best results, albeit with low ee in the major regioisomer, was obtained in the reaction of 37a with the NO precursor 38 in the presence of the chiral macrocyclic barbiturate receptor 39 (Scheme 11).…”