Supramolecular catalysis. Part 2: artificial enzyme mimics

Abstract

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.

“Helix‐in‐Helix” Superstructure Formation through Encapsulation of Fullerene‐Bound Helical Peptides within a Helical Poly(methyl methacrylate) Cavity

“…The development of host molecules, supramolecules, and polymers that possess a unique confined nano‐space suitable for encapsulating specific guests has been attracting significant attention1 because of their broad applications toward molecular recognition, sensing, separation1c,1g,1j and catalysis,1h,1k,1l,1o,1p as well as electronic and optoelectronic materials 1d. Cyclic host molecules, such as modified cyclodextrins1a,1g and self‐assembled metal–organic cages1f,1h,1i,1l–1n and organic nanocapsules,1c are among the most extensively investigated host molecules.…”

One-pot synthesis of tetrahydro-4H-chromenes by supramolecular catalysis in water

“…7 Host-guest models are among essential catalytic systems for supramolecular catalysis. Natural or well-designed articial supramolecular hosts have been employed in organic synthesis, such as crown ethers, cyclodextrins (CDs), calixarenes, cucurbiturils and cyclophanes, etc.…”

Transition Metal-free Epoxidation of Alkenes Based on the Existence of (2- hydroxypropyl)-β-CD

“…Cyclodextrins, which wre cyclic oligosaccharides with hydrophobic cavities, can promote oxidation with excellent selectivity via non-covalent bonding of host-guest complexes [12] as seen in enzymes; and the corresponding reports [13][14][15][16] about epoxidation and organic synthesis catalyzed by hp--cyclodextrin and its derivatives in water involving the formation of host-guest complexes are increasing. The inclusion rests with the space structures, size, and hydrogen bonds of the guest [17,18].…”