Reactivity within a confined self-assembled nanospace.

Confined nanospaces in which reactions can take place, have been created by various approaches such as molecular capsules, zeolites and micelles. In this tutorial review we focus on the application of self-assembled nanocapsules with well-defined cavities as nanoreactors for organic and metal catalysed transformations. The self-assembly of nanocapsules based on noncovalent bonds such as hydrogen bonds and metal-ligand interactions is discussed to introduce the properties of the building blocks and capsules thereof. We will elaborate on the encapsulation effects that can be expected when reactions are carried out in a capsule-protected environment. Subsequently, literature examples will be described in which self-assembled nanocapsules are applied as nanoreactors, for various types of organic and metal catalysed reactions.

[1]  S. Jockusch,et al.  Controlling photoreactions with restricted spaces and weak intermolecular forces: exquisite selectivity during oxidation of olefins by singlet oxygen. , 2007, Journal of the American Chemical Society.

[2]  Michael D. Pluth,et al.  Acid Catalysis in Basic Solution: A Supramolecular Host Promotes Orthoformate Hydrolysis , 2007, Science.

[3]  Karlheinz Drauz,et al.  Enzyme Catalysis in Organic Synthesis , 1995 .

[4]  K N Houk,et al.  Why enzymes are proficient catalysts: beyond the Pauling paradigm. , 2005, Accounts of chemical research.

[5]  M. Tamura,et al.  Diels-Alder in Aqueous Molecular Hosts: Unusual Regioselectivity and Efficient Catalysis , 2006, Science.

[6]  J. Reek,et al.  Assembly of Encapsulated Transition Metal Catalysts. , 2001, Angewandte Chemie.

[7]  J. Reek,et al.  High-precision catalysts: regioselective hydroformylation of internal alkenes by encapsulated rhodium complexes. , 2006, Journal of the American Chemical Society.

[8]  Catelijne H M Amijs,et al.  Metallasupramolecular architectures, an overview of functional properties and applications. , 2006, Dalton transactions.

[9]  Kumar Biradha,et al.  Molecular paneling via coordination , 2001 .

[10]  J. Atwood,et al.  Structural classification and general principles for the design of spherical molecular hosts. , 1999, Angewandte Chemie.

[11]  J. Rebek,et al.  The ins and outs of molecular encapsulation. , 2004, Organic & biomolecular chemistry.

[12]  Johannes A A W Elemans,et al.  Self-assembled nanoreactors. , 2005, Chemical reviews.

[13]  K. Raymond,et al.  Scope and mechanism of the C-H bond activation reactivity within a supramolecular host by an iridium guest: a stepwise ion pair guest dissociation mechanism. , 2006, Journal of the American Chemical Society.

[14]  P. Dalko.  Enantioselective organocatalysis : reactions and experimental procedures , 2007 .

[15]  J. Rebek,et al.  Self-Assembled Molecular Capsule Catalyzes a Diels−Alder Reaction , 1998 .

[16]  M. Fujita,et al.  Alkane oxidation via photochemical excitation of a self-assembled molecular cage. , 2004, Journal of the American Chemical Society.

[17]  D. Truhlar,et al.  Mechanisms and free energies of enzymatic reactions. , 2006, Chemical reviews.

[18]  J. Lehn,et al.  Supramolecular Chemistry: Receptors, Catalysts, and Carriers , 1985, Science.

[19]  M. Fujita,et al.  Cavity-directed synthesis of labile silanol oligomers within self-assembled coordination cages. , 2001, Journal of the American Chemical Society.

[20]  K. Raymond,et al.  Highly selective supramolecular catalyzed allylic alcohol isomerization. , 2007, Journal of the American Chemical Society.

[21]  M. J. Wilkinson,et al.  New directions in supramolecular transition metal catalysis. , 2005, Organic & biomolecular chemistry.

[22]  Arjan W. Kleij,et al.  Encapsulated transition metal catalysts comprising peripheral Zn(II)salen building blocks: template-controlled reactivity and selectivity in hydroformylation catalysis. , 2005, Chemical communications.

[23]  Supramolecular Catalysis in Transition , 1998 .

[24]  J. Rebek.  Simultaneous encapsulation: molecules held at close range. , 2005, Angewandte Chemie.

[25]  F. Diederich,et al.  Book review: Metal-catalyzed cross-coupling reactions. F. Diederich and P. J. Stang (eds) Wiley–VCH, Weinheim, 1998. xxi + 517 pages, £85 ISBN 3–527–29421–X , 1998 .

[26]  L. Pauling,et al.  Nature of Forces between Large Molecules of Biological Interest , 1948, Nature.

[27]  M. Fujita,et al.  Coordination assemblies from a Pd(II)-cornered square complex. , 2005, Accounts of chemical research.

[28]  C. D. de Koster,et al.  Bisphosphine based hetero-capsules for the encapsulation of transition metals. , 2006, Chemical communications.

[29]  D. Cram.  Cavitands: Organic Hosts with Enforced Cavities , 1983, Science.

[30]  P. V. Leeuwen,et al.  Homogeneous Catalysis: Understanding the Art , 2004 .

[31]  R. Cacciapaglia,et al.  Effective molarities in supramolecular catalysis of two-substrate reactions. , 2004, Accounts of chemical research.

[32]  K. Raymond,et al.  Supramolecular assembly dynamics , 2002, Proceedings of the National Academy of Sciences of the United States of America.

[33]  Seang Tan,et al.  Cryopreservation: Fertility after intact ovary transplantation , 2002, Nature.

[34]  D. Fiedler,et al.  Selective molecular recognition, C-H bond activation, and catalysis in nanoscale reaction vessels. , 2004, Accounts of chemical research.

[35]  D. Fiedler,et al.  Supramolecular catalysis of unimolecular rearrangements: substrate scope and mechanistic insights. , 2006, Journal of the American Chemical Society.

[36]  M. Dewar,et al.  Alternative view of enzyme reactions. , 1985, Proceedings of the National Academy of Sciences of the United States of America.

[37]  M. Fujita,et al.  Crystallographic observation of an olefin photodimerization reaction that takes place via thermal molecular tumbling within a self-assembled host. , 2006, Chemical communications.

[38]  J. Reek,et al.  Encapsulation of transition metal catalysts by ligand-template directed assembly. , 2004, Journal of the American Chemical Society.

[39]  C. J. Elsevier,et al.  The handbook of homogeneous hydrogenation , 2006 .

[40]  D. Cram.  Molecular container compounds , 1992, Nature.

[41]  B. Gibb,et al.  Well-defined, organic nanoenvironments in water: the hydrophobic effect drives a capsular assembly. , 2004, Journal of the American Chemical Society.

[42]  M. Fujita,et al.  Cavity-directed, highly stereoselective [2+2] photodimerization of olefins within self-assembled coordination cages. , 2002, Angewandte Chemie.

[43]  Michael D. Pluth,et al.  Reversible guest exchange mechanisms in supramolecular host-guest assemblies. , 2006, Chemical Society reviews.

[44]  M. Fujita,et al.  Wacker Oxidation in an Aqueous Phase through the Reverse Phase-Transfer Catalysis of a Self-Assembled Nanocage , 2000 .

[45]  M. Fujita,et al.  Cavity-directed synthesis within a self-assembled coordination cage: highly selective [2 + 2] cross-photodimerization of olefins. , 2003, Journal of the American Chemical Society.

[46]  A. Lützen.  Self-assembled molecular capsules--even more than nano-sized reaction vessels. , 2005, Angewandte Chemie.

[47]  W. Motherwell,et al.  Recent progress in the design and synthesis of artificial enzymes , 2001 .

[48]  A. J. Kirby,et al.  Enzyme Mechanisms, Models, and Mimics , 1996 .

[49]  Arjan W. Kleij,et al.  Ligand-template directed assembly: an efficient approach for the supramolecular encapsulation of transition-metal catalysts. , 2006, Chemistry.

[50]  S. Nguyen,et al.  Artificial Enzymes Formed through Directed Assembly of Molecular Square Encapsulated Epoxidation Catalysts. , 2001, Angewandte Chemie.

[51]  J. Rebek,et al.  Selectivity in an encapsulated cycloaddition reaction. , 2002, Organic letters.

[52]  A. Greer.  Organic chemistry: Molecular cross-talk , 2007, Nature.

[53]  Takumi Yamaguchi,et al.  Unusual [2+4] and [2+2] cycloadditions of arenes in the confined cavity of self-assembled cages. , 2007, Journal of the American Chemical Society.