Strategien und Taktiken für die metallgesteuerte Synthese von Rotaxanen, Knoten, Catenanen und Verschlingungen höherer Ordnung

Beves, Jonathon E.; Blight, Barry A.; Campbell, Christopher J.; Leigh, David A.; McBurney, Roy T.

doi:10.1002/ange.201007963

Cited by 168 publications

(11 citation statements)

References 707 publications

(729 reference statements)

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“…[1] Although direct selfassembly of these components through intermolecular hydrogen bonding [2] and/or p-stacking interactions [3] is possible in some unique recognition systems, the use of an ionic template to bridge and preorganize them remains a commonly applied strategy. In addition to anions, [4] transition-metal cations [5] are the most frequently used ionic templates because their predictable chelation numbers and geometries allow precise arrangement of the precursor components of the [2]catenane. Pyridines, bipyridines, and their derivatives, which have strong binding affinities to transition-metal ions, have generally been used as recognition units in such systems (Figure 1 a), and have led to the construction of many elegant and [*] S.…”

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confidence: 99%

“…functional [2]catenanes. [5] Although the binding of oligo-(ethylene glycol) chains to alkali metal ions has long been applied in the synthesis of crown ethers, [6] we were unaware of any examples of the use of alkali metal ions to template the association of two oligo(ethylene glycol) chains in an orthogonal geometry (Figure 1 b) to facilitate the self-assem-bly of the corresponding catenanes or rotaxanes. We suspected, however, that if chemically relatively inert, readily accessible, and readily derivatized oligo(ethylene glycol) units could serve as primary recognition units for the construction of interlocked molecules, then facile new syntheses of structurally simple interlocked molecular switches capable of performing interesting functions might be possible.…”

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Synthesis of a [2]Catenane from the Sodium Ion Templated Orthogonal Arrangement of Two Diethylene Glycol Chains

et al. 2013

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An important feature for the efficient construction of a [2]catenane is the appropriate alignment of the individual precursor molecular components. [1] Although direct selfassembly of these components through intermolecular hydrogen bonding [2] and/or p-stacking interactions [3] is possible in some unique recognition systems, the use of an ionic template to bridge and preorganize them remains a commonly applied strategy. In addition to anions, [4] transition-metal cations [5] are the most frequently used ionic templates because their predictable chelation numbers and geometries allow precise arrangement of the precursor components of the [2]catenane. Pyridines, bipyridines, and their derivatives, which have strong binding affinities to transition-metal ions, have generally been used as recognition units in such systems (Figure 1 a), and have led to the construction of many elegant and[*] S.

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Synthesis of a [2]Catenane from the Sodium Ion Templated Orthogonal Arrangement of Two Diethylene Glycol Chains

et al. 2013

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“…This is, of course, one of the tactics Nature utilizes to control the reactivity and selectivity of enzymes. [13] It occurred to us that the incorporation of a secondary amine into a mechanically interlocked molecule (MIM), [14] such as a [2]rotaxane, [15] might be a way to conceptually emulate Nature. This strategy would convert a simple Lewis base into a bulky Lewis base partner for FLP chemistry without the restriction of covalent modification.The secondary amine (aniline) 1, which contains 1,3dimethylphenyl and 1,3-dimethylbenzyl groups, was selected as the Lewis basic axle for incorporation into a [2]rotaxane.…”

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Heterolytic Activation of H₂ Using a Mechanically Interlocked Molecule as a Frustrated Lewis Base

et al. 2012

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A frustrated Lewis pair (FLP) is an intra-or intermolecular combination of a Lewis acid and a Lewis base in which steric hindrance inhibits the formation of a classical Lewis donoracceptor adduct. A consequence of the unquenched Lewis acidity and basicity is unprecedented reactivity, including the heterolytic cleavage of H 2 molecules [1] and activation of small molecules, such as CO 2 , [2] N 2 O, [3] NO, [4] SO 2 , [5] alkenes, [6] and alkynes. [7] The FLP concept [8] has been recently exploited for the development of stoichiometric reductions of anilines to cyclohexylamines, [9] and of metal-free catalysts for hydrogenation of polar substrates [8,10] and 1,1-disubstituted olefins. [11] The steric bulk, which inhibits the formation of Lewis acid-base adducts in FLP chemistry, has traditionally been attached directly to the Lewis acidic and basic atoms. [7a] For example, the phosphines, [1a,b] amines, [12] and boranes [1a,b] that have been used to elicit FLP reactivity all contain either bulky alkyl or aryl substituents directly bonded to the heteroatom. As this requirement can be synthetically challenging and thereby somewhat restrictive, we sought an alternate strategy to sterically encumber Lewis bases. To this end, we have considered the notion of converting a Lewis base that would normally form an adduct with the Lewis acid B(C 6 F 5 ) 3 into one that participates as a partner in an FLP.One avenue to restrict access to the reactivity of a particular functional group is to bury it inside some sort of cavity, so as to preclude access from other selected reagents. This is, of course, one of the tactics Nature utilizes to control the reactivity and selectivity of enzymes. [13] It occurred to us that the incorporation of a secondary amine into a mechanically interlocked molecule (MIM), [14] such as a [2]rotaxane, [15] might be a way to conceptually emulate Nature. This strategy would convert a simple Lewis base into a bulky Lewis base partner for FLP chemistry without the restriction of covalent modification.The secondary amine (aniline) 1, which contains 1,3dimethylphenyl and 1,3-dimethylbenzyl groups, was selected as the Lewis basic axle for incorporation into a [2]rotaxane. Scheme 1 outlines the synthesis of the two neutral [2]rotaxanes [1&24 C6] and [1&22 C6] with differently sized macrocyclic wheels (24-and 22-membered) and the axle 1. The key feature of the synthesis is the ring-closing metathesis reaction facilitated by Grubbs first-generation catalyst. [16] This reaction occurs while hydrogen-bonding and ion-dipole templating interactions between the anilinium ion of the protonated axle [1-H] + and the oxygen atoms of the crown ether hold the axle and wheel in close proximity; thus favoring [2]rotaxane formation. [17] [2]Rotaxanes [1&24 C6] and [1&22 C6] were isolated in moderate yields after reduction of the residual double bonds created from olefin metathesis and subsequent neutralization with base. This [2]rotaxane design utilizes a short axle with only two nonhydrogen atoms (NH and CH 2 ) betwe...

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“…Although 12·4 PF 6 exists presumably as a mixture of four stereoisomers, the signals for the stereoisomers overlap within the resolution limits of both 1 H and 13 C NMR spectroscopic techniques. 1 .90 (AA'XX', J = 6.7, 2.4 Hz, 2 H), 6.82 (AA'XX', J = 5.9 Hz, 2 H), 6.34 (s, 2 H), 6.13 (d,J = 7.8 Hz,2 H),4 H),6 H),6 H),.03 (m, 2 H), 4.00-3.68 (m, 20 H), 3.59 (t, J = 10.1 Hz, 2 H), 3.16 (br s, 2 H), 2.41 (s, 6 H), 2.34 (d, J = 8.1 Hz, 2 H), 1.62 ppm (s, 18 H); 13 C NMR (CD 3 CN,125 MHz,298 K): d = 166.3,151.7,150.0,146.3,145.8,145.8,145.2,144.6,144.3,141.2,140.1,140.0,137.5,137.4,136.8,136.6,132.6,132.1,132.0,130.8,130.7,130.6,129.1,129.0,127.7,127.6,127.4,126.7,127.6,127.4,126.7,125.6,125.3,125.1,124.5,115.0,109.2,105.0,81.8,72.1,71.9,70.6,70.5,70.3,68.9,68.9,…”

Section: Synthesis Of Compoundmentioning

confidence: 99%

Three‐Dimensional Architectures Incorporating Stereoregular Donor–Acceptor Stacks

Cao

Jurı́ček

Brown

et al. 2013

Chemistry A European J

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We report the synthesis of two [2]catenane-containing struts that are composed of a tetracationic cyclophane (TC(4+)) encircling a 1,5-dioxynaphthalene (DNP)-based crown ether, which bears two terphenylene arms. The TC(4+) rings comprise either 1) two bipyridinium (BIPY(2+)) units or 2) a BIPY(2+) and a diazapyrenium (DAP(2+)) unit. These degenerate and nondegenerate catenanes were reacted in the presence of Cu(NO3)2⋅2.5 H2O to yield Cu-paddlewheel-based MOF-1050 and MOF-1051. The solid-state structures of these MOFs reveal that the metal clusters serve to join the heptaphenylene struts into grid-like 2D networks. These 2D sheets are then held together by infinite donor-acceptor stacks involving the [2]catenanes to produce interpenetrated 3D architectures. As a consequence of the planar chirality associated with both the DNP and hydroquinone (HQ) units present in the crown ether, each catenane can exist as four stereoisomers. In the case of the nondegenerate (bistable) catenane, the situation is further complicated by the presence of translational isomers. Upon crystallization, however, only two of the four possible stereoisomers--namely, the enantiomeric RR and SS forms--are observed in the crystals. An additional element of co-conformational selectivity is present in MOF-1051 as a consequence of the substitution of one of the BIPY(2+) units by a DAP(2+) unit: only the translational isomer in which the DAP(2+) unit is encircled by the crown ether is observed. The overall topologies of MOF-1050 and MOF-1051, and the selective formation of stereoisomers and translational isomers during the kinetically driven crystallization, provide evidence that weak noncovalent bonding interactions play a significant role in the assembly of these extended (super)structures.

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Strategien und Taktiken für die metallgesteuerte Synthese von Rotaxanen, Knoten, Catenanen und Verschlingungen höherer Ordnung

Cited by 168 publications

References 707 publications

Synthesis of a [2]Catenane from the Sodium Ion Templated Orthogonal Arrangement of Two Diethylene Glycol Chains

Synthesis of a [2]Catenane from the Sodium Ion Templated Orthogonal Arrangement of Two Diethylene Glycol Chains

Heterolytic Activation of H₂ Using a Mechanically Interlocked Molecule as a Frustrated Lewis Base

Three‐Dimensional Architectures Incorporating Stereoregular Donor–Acceptor Stacks

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Strategien und Taktiken für die metallgesteuerte Synthese von Rotaxanen, Knoten, Catenanen und Verschlingungen höherer Ordnung

Cited by 168 publications

References 707 publications

Synthesis of a [2]Catenane from the Sodium Ion Templated Orthogonal Arrangement of Two Diethylene Glycol Chains

Synthesis of a [2]Catenane from the Sodium Ion Templated Orthogonal Arrangement of Two Diethylene Glycol Chains

Heterolytic Activation of H2 Using a Mechanically Interlocked Molecule as a Frustrated Lewis Base

Three‐Dimensional Architectures Incorporating Stereoregular Donor–Acceptor Stacks

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Heterolytic Activation of H₂ Using a Mechanically Interlocked Molecule as a Frustrated Lewis Base