Artificial Organic Host Molecules for Anions

Transition-Metal Receptor Systems for the Selective Recognition and Sensing of Anionic Guest Species

The design of artificial catalysts able to compete with the catalytic proficiency of enzymes is an intense subject of research. Non-covalent interactions are thought to be involved in several properties of enzymatic catalysis, notably (i) the confinement of the substrates and the active site within a catalytic pocket, (ii) the creation of a hydrophobic pocket in water, (iii) self-replication properties and (iv) allosteric properties. The origins of the enhanced rates and high catalytic selectivities associated with these properties are still a matter of debate. Stabilisation of the transition state and favourable conformations of the active site and the product(s) are probably part of the answer. We present here artificial catalysts and biomacromolecule hybrid catalysts which constitute good models towards the development of truly competitive artificial enzymes.

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Supramolecular catalysis. Part 2: artificial enzyme mimics

Artificial Receptors for the Recognition of Phosphorylated Molecules Amanda E. Hargrove, Sonia Nieto, Tianzhi Zhang, Jonathan L. Sessler,* and Eric V. Anslyn* Department of Chemistry and Biochemistry, University of Texas at Austin, 1 University Station A5300, Austin, Texas 78712-0165, United States Universidad de Zaragoza, Zaragoza, Spain Henkel Corporation, Rocky Hill, Connecticut 06067 Department of Chemistry, Yonsei University, Seoul, 120-749 Korea

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Artificial receptors for the recognition of phosphorylated molecules

Noncovalent binding between guanidinium and anionic groups: focus on biological- and synthetic-based arginine/guanidinium interactions with phosph[on]ate and sulf[on]ate residues.

The optically active (4S,8S)-4, 8-bis(hydroxymethyl)-1,5,7-triazabicyclo[4.4.0]dec-5-ene ((S,S)-1) has been synthesized in nine steps from L-asparagine with a total yield of 5.1%. Similarly, the enantiomer (R,R)-1 has been prepared from D-asparagine. (S,S)- and (S,S)-1 are representative examples of rigid and functionalized bicyclic guanidine systems and constitute useful intermediates in the construction of chiral selective anion-receptor molecules.

Anion-receptor molecules: Synthesis of a chiral and functionalized binding subunit, a bicyclic guanidinium group derived from L- or D- asparagine

Selective complexation of adenosine monophosphate nucleotides by rigid bicyclic guanidinium abiotic receptors

Transport of adenine mono- and dinucleoside monophosphates across liquid membranes and extraction of oligonucleotides with synthetic carriers

Molecular recognition of biomolecules by synthetic receptors requires modular assembly of various components to complement the molecular characteristics (sizes, topologies, and functional groups) of the substrate. A number of receptors for biorelevant molecules containing oxoanions have been assembled from a bicyclic chiral guanidine subunit. Several receptors accelerate or catalyze reactions proceeding through anionic transition states. Among the structures recently prepared, a receptor incorporating a calix(6)arene subunit has been developed, showing high affhity for phosphocholine derivatives. Chains of tetraguanidinium sulfates form double helices in solution. These substances strongly induce formation of a-helical conformations in Asp rich peptides.

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Armando Salmerón

Papers

Anion-receptor molecules: Synthesis of a chiral and functionalized binding subunit, a bicyclic guanidinium group derived from L- or D- asparagine

Selective complexation of adenosine monophosphate nucleotides by rigid bicyclic guanidinium abiotic receptors

Transport of adenine mono- and dinucleoside monophosphates across liquid membranes and extraction of oligonucleotides with synthetic carriers

Total synthesis of non-natural compounds for molecular recognition. The double challenge

Total Synthesis of Non-Natural Compounds for Molecular Recognition: The Double Challenge