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614 results on '"Otto, Sijbren"'

106. Dynamic Combinatorial Chemistry

Author

Reek, Joost N.H., Otto, Sijbren, and Synthetic Organic Chemistry

Abstract

This long-awaited first book on this exciting new field in organic and supramolecular chemistry explains the fundamentals as well as possible applications of DCC. Authored by the Who's Who of DCC it spans the whole range of topics: catalysts, sensors, polymers, ligands, receptors, concluding with a look at future developments and perspectives. All set to become the standard text in the field, this one-stop reference contains everything organic, catalytic, polymer, physical and biochemists need to know.

Published
2010

111. Trends and Perspectives

Author

Otto, Sijbren, Reek, Joost N.H., and Synthetic Organic Chemistry

Subjects
emergent properties, autocatalysis, molecular network, systems chemistry, self-replication
Published
2010

115. Dynamic combinatorial optimization of a neutral receptor that binds inorganic anions in aqueous solution

Author

Otto, Sijbren, Kubik, Stefan, Michael H. W. Lam, and Wai-Yeung Wong

Subjects
Anions -- Atomic properties, Anions -- Research, Peptides -- Atomic properties, Peptides -- Research, Chemistry
Abstract

Dynamic combinatorial chemistry can be used to optimize the binding properties of bis-(cyclopeptide) 2 toward anions in aqueous solution. Results demonstrate that dynamic combinatorial optimization of designed receptors can be a useful strategy, bringing synthetic receptors with efficiencies approaching those of proteins one step closer.

Published
2003

117. Mechanism of Building Block Exchange in Stacks of Self-Replicating Macrocycles.

Author

Mattia, Elio, Pal, Asish, Leonetti, Giulia, and Otto, Sijbren

Subjects
MACROCYCLIC compound synthesis, MOLECULAR self-assembly, EXCHANGE reactions
Abstract

Self-replicating molecules containing labile reversible covalent bonds are becoming increasingly topical. Yet their robustness to component exchange and the threat of loss of information has received very little attention. We show here that supramolecular interactions can efficiently protect self-replicating molecules from otherwise rapid component exchange. [ABSTRACT FROM AUTHOR]

Published
2017
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118. A new cyclic pseudopeptide receptor for Li from a dynamic combinatorial library

Author

furlan, Ricardo L.E., Yiu-Fai Ng, Otto, Sijbren, and Sanders, Jeremy K.M.

Subjects
Lithium -- Research, Peptides -- Research, Chemistry
Abstract

Research investigating the dynamic combinatorial chemistry of pseudopeptides of lithium is presented. Particular attention is given to cyclic pseudoreceptors of cyclic peptides and to applications of the technique of hydrazone exchange.

Published
2001

125. Metal-ion induced amplification of three receptors from dynamic combinatorial libraries of peptide-hydrazones

Author

Roberts, Sarah L., Furlan, Ricardo L.E., Otto, Sijbren, Sanders, Jeremy K.M., and Synthetic Organic Chemistry

Abstract

Three building blocks of general structure (MeO)2CH–aromatic linker–Pro–amino acid–NHNH2 have been prepared and tested in acid-catalysed dynamic combinatorial libraries. Exposure of these libraries to LiI and NaI led to the amplification of three macrocyclic pseudopeptide receptors. The receptors were isolated and their interactions with LiI and NaI were analysed using NMR, IR and ITC. Binding of the metal ions to the receptors is invariably entropy-driven. Nevertheless, all receptors were found to be flexible with substantial conformational rearrangements accompanying guest binding. This type of receptor is extremely difficult to access through rational design and the fact that dynamic combinatorial chemistry allows facile access to these challenging molecules underlines the power of the dynamic approach.

Published
2003

128. Squeezing a synthetic ionophore and mechanistic insight out of a lipid bilayer

Author

Otto, Sijbren, Osifchin, Manette, and Regen, Steven L.

Subjects
Amphotericin B -- Research, Bilayer lipid membranes -- Research, Chemical reaction, Rate of -- Research, Ionophores -- Research, Thin films -- Research, Chemistry
Abstract

Research is presented describing the phase-induced expulsion of a synthetic ionophore from a phospholipid bilayer. The expulsion provides a detailed mechanistic insight into the characteristics of the transport-active species.

Published
1999

129. Modular control over the selectivity of self-assembling and membrane spanning ion conductors

Author

Otto, Sijbren, Osifchin, Manette, and Regen, Steven L.

Subjects
Ionophores -- Research, Organic compounds -- Synthesis, Chemistry
Abstract

A synthesis of an ionophore having a 23,24-bisnor-5-cholenic acid as the hydrophobic unit and permine as the conducting module is shown to be active for H+/OH- transport bu not for Na+ ion transport. An anlogous ionophore having exactly the opposite properties has been produced by replacement of of the polymaine moiety by a polymer chain. Kinetic evidences demonstrating that membrane-spanning dimers are the active species in both cases were also obtained.

Published
1999

130. A chiral Lewis-acid-catalyzed Diels-Alder reaction. Water-enhanced enantioselectivity

Author

Otto, Sijbren, Boccaletti, Giovanni, and Engberts, Jan B.F.N.

Subjects
Diels-Alder reaction -- Research, Water -- Usage, Chirality -- Research, Enantiomers -- Research, Chemistry
Abstract

A study was conducted on the enantioselectivity of a Lewis-acid-catalyzed Diels-Alder reaction of 3-phenyl-1-(2-pyridyl)-2-propen-1-one with cyclopentadiene in water. Results showed that the coordination of chiral alpha-amino acids to a catalytically active metal ion can induce enantioselectivity in the water-based Lewis-acid-catalyzed Diels-Alder reaction. Moreover, the enantioselectivity is greater when water is used as a solvent instead of other organic solvents.

Published
1998

141. (Re-)Directing Oligomerization of a Single Building Block into Two Specific Dynamic Covalent Foldamers through pH

Author

Jin, Yulong, Mandal, Pradeep K., Wu, Juntian, Böcher, Niklas, Huc, Ivan, and Otto, Sijbren

Abstract

Dynamic foldamers are synthetic folded molecules which can change their conformation in response to an external stimulus and are currently at the forefront of foldamer chemistry. However, constitutionally dynamic foldamers, which can change not only their conformation but also their molecular constitution in response to their environment, are without precedent. We now report a size- and shape-switching small dynamic covalent foldamer network which responds to changes in pH. Specifically, acidic conditions direct the oligomerization of a dipeptide-based building block into a 16-subunit macrocycle with well-defined conformation and with high selectivity. At higher pH the same building block yields another cyclic foldamer with a smaller ring size (9mer). The two foldamers readily and repeatedly interconvert upon adjustment of the pH of the solution. We have previously shown that addition of a template can direct oligomerization of the same building block to yet other rings sizes (including a 12mer and a 13mer, accompanied by a minor amount of 14mer). This brings the total number of discrete foldamers that can be accessed from a single building block to five. For a single building block system to exhibit such highly diverse structure space is unique and sets this system of foldamers apart from proteins. Furthermore, the emergence of constitutional dynamicity opens up new avenues to foldamers with adaptive behavior.

Published
2023
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142. Enantioselective Self-Replicators

Author

Yang, Shuo, Geiger, Yannick, Geerts, Marc, Eleveld, Marcel J., Kiani, Armin, and Otto, Sijbren

Abstract

Self-replicating molecules provide a simple approach for investigating fundamental processes in scenarios of the emergence of life. Although homochirality is an important aspect of life and of how it emerged, the effects of chirality on self-replicators have received only little attention so far. Here, we report several self-assembled self-replicators with enantioselectivity that emerge spontaneously and grow only from enantiopure material. These require a relatively small number of chiral units in the replicators (down to eight) and in the precursors (down to a single chiral unit), compared to the only other enantioselective replicator reported previously. One replicator was found to incorporate material of its own handedness with high fidelity when provided with a racemic mixture of precursors, thus sorting (L)- and (D)-precursors into (L)- and (D)-replicators. Systematic studies reveal that the presence or absence of enantioselectivity depends on structural features (ring size of the replicator) that appear to impose constraints on its supramolecular organization. This work reveals new aspects of the little researched interplay between chirality and self-replication and represents another step toward the de novo synthesis of life.

Published
2023
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