Dynamic Combinatorial Discovery of a [2]-Catenane and its Guest-Induced Conversion into a Molecular Square Host

West, Kevin R.; Ludlow, R. Frederick; Corbett, Peter; Besenius, Pol; Mansfeld, Friederike M.; Cormack, Peter A. G.; Sherrington, David C.; Goodman, Jonathan M.; Stuart, Marc C. A.; Otto, Sijbren

doi:10.1021/ja801508q

Cited by 75 publications

(63 citation statements)

References 41 publications

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“…[21] On the contrary, when the mixture was filtered after 30 min, homo-[2+2]·toluene was selectively precipitated in high yield and no significant amounts of boronic esters were observed in the filtrate (entry 2). The same tendency was observed in the case of benzene except that the rate of precipitation was slower than in toluene and a significant amount of homo-[2+2] was observed in the filtrate after a shorter reaction time (entries [4][5][6] were present in solution, only one of those macrocyclic boronic esters could precipitate selectively, depending on the nature of the host molecule. [22] …”

Section: Resultssupporting

confidence: 65%

“…[1] Most of the reported examples are based on the coordination of multidentate nitrogen ligands to metal ions, [2,3] and relatively few examples are known in which reversible covalent linkages [4] such as S À S [5] or C=N [6] bonds are employed for the dynamic construction of host molecules. In these cases, the reaction is usually carried out under either acidic or basic conditions, and the yield and the selectivity of formation of the host molecule are often dissatisfying.…”

Section: Introductionmentioning

confidence: 99%

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Crystallization‐Controlled Dynamic Self‐Assembly and an On/Off Switch for Equilibration Using Boronic Ester Formation

Takahagi

Iwasawa

2010

Chemistry A European J

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Macrocyclic boronic esters of different sizes can be prepared selectively from the same starting diboronic acid and 1,2-diol by means of an interesting dynamic self-assembly phenomena. More specifically, two kinds of macrocyclic boronic esters could be formed diastereoselectively and nearly quantitatively under neutral conditions by the addition of an appropriate guest molecule that acts as a template. Although a mixture of tetrol 1 and di(boronic acid) 2 in methanol gave only insoluble polymeric boronic esters, a soluble macrocyclic boronic ester, homo-[2+2], was obtained selectively in the presence of toluene as a guest molecule. Furthermore, when benzene was employed as a guest molecule, the selective formation of another macrocyclic boronic ester, hetero-[3+3], occurred. Interestingly, each of these macrocycles could be converted into the other in the presence of methanol and the appropriate guest molecule; however, under aprotic conditions, guest molecules encaged by the macrocyclic boronic ester could be exchanged without affecting its structure. Thus the presence or absence of a protic solvent could be used as a regulator to switch on or off the dynamic equilibrium of the system. In addition, investigation of the effect of reaction time, direct observation of the reaction mixture by NMR spectroscopy, and carrying out the reaction using optically active tetrol suggested that precipitation plays an essentially important role in the selective formation of the macrocyclic boronic esters. Thus, although both of [2+2] and [3+3] were present as solutes in the reaction mixture, the type of added guest molecule induced the selective precipitation of only one form of macrocyclic boronic ester, hence displacing the equilibrium of the system.

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Section: Resultssupporting

confidence: 65%

Section: Introductionmentioning

confidence: 99%

Crystallization‐Controlled Dynamic Self‐Assembly and an On/Off Switch for Equilibration Using Boronic Ester Formation

Takahagi

Iwasawa

2010

Chemistry A European J

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“…The recent rise of dynamic covalent chemistry (10) using reversible chemical reactions under thermodynamic control has led to an increasing number of catenane syntheses that are either designed to lead to a particular structure (for recent examples, see 9, 11-19) or result from unpredictable dynamic combinatorial selection (20,21). The advantage of either of these dynamic strategies is the possibility of recycling un-interlocked components, hence increasing the yield of the desired structure.…”

mentioning

confidence: 99%

Dynamic combinatorial synthesis of a catenane based on donor–acceptor interactions in water

Au‐Yeung

Pantoş

Sanders

2009

Proc. Natl. Acad. Sci. U.S.A.

139

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A new type of neutral donor-acceptor [2]-catenane, containing both complementary units in the same ring was synthesized from a dynamic combinatorial library in water. The yield of the water soluble [2]-catenane is enhanced by increasing either buildingblock concentrations or ionic strength, or by the addition of an electron-rich template. NMR spectroscopy demonstrates that the template is intercalated between the 2 electron-deficient naphthalenediimide units of the catenane.dynamic combinatorial chemistry ͉ molecular recognition W e report here the spontaneous assembly of a donoracceptor (D-A) [2]-catenane from a dynamic combinatorial library (DCL) in water. Unusually, this is a D-A catenane that contains the electron-deficient and electron-rich aromatic moieties in the same ring. Owing to their complex topology and the resulting synthetic challenge, mechanically interlocked molecules such as catenanes have captivated chemists for a long time (1). With advances in the efficient templated synthesis of these interlocked structures, applications of these interesting molecules have been found in molecular electronic devices, such as switches, motors, color displays, and molecular memory (2-5).Conventional catenane synthesis relies on the use of noncovalent interactions to preorganize precursors in a suitable configuration that favors the formation of an interlocked structure, employing an irreversible, kinetically controlled chemical reaction as the final catenating step (for recent examples, see 6-9). The recent rise of dynamic covalent chemistry (10) using reversible chemical reactions under thermodynamic control has led to an increasing number of catenane syntheses that are either designed to lead to a particular structure (for recent examples, see 9, 11-19) or result from unpredictable dynamic combinatorial selection (20,21). The advantage of either of these dynamic strategies is the possibility of recycling un-interlocked components, hence increasing the yield of the desired structure.Interactions between electron-rich aromatics, such as dialkoxynaphthalene (DN) and tetrathiafulvalene (TTF), and electron deficient aromatics, like naphthalenediimide (NDI) and paraquat, have been extensively used in the preparation of catenanes (9,22,23). The vast majority of these catenane constructions rely on kinetically controlled reactions. Some examples of thermodynamically controlled syntheses of these structures include the neutral [2]-catenanes featuring zincpyridine coordination (24) and alkene metathesis as the ringclosing reactions (25). More recently, Stoddart and coworkers reported the iodide-catalyzed self-assembly of paraquat-based cationic D-A [2]-(16) and [3]-catenanes (14) from separate -donor and -acceptor rings using thermodynamically controlled nucleophilic substitution. Most of the examples of D-A catenane syntheses depend on a preformed, -rich crown ether ring containing electron-donor units, and the subsequent formation of new electron-deficient rings followed by catenation. Hence, the resulting catenanes...

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“…In the absence of any template molecules the dynamic mixture was dominated by a set of isomeric 2-catenanes (8), consisting of two interlocked tetrameric macrocycles, as reported previously (Figure 1 a). [19] Only minor amounts of four isomeric tetramer macrocycles (9) were obtained. Exposing the dynamic molecular network to TSA 6 induced a dramatic shift in the product distribution, in favor of the tetrameric macrocycles (Figure 1 b).…”

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confidence: 99%

Transient Substrate‐Induced Catalyst Formation in a Dynamic Molecular Network

et al. 2014

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In biology enzyme concentrations are continuously regulated, yet for synthetic catalytic systems such regulatory mechanisms are underdeveloped. We now report how a substrate of a chemical reaction induces the formation of its own catalyst from a dynamic molecular network. After complete conversion of the substrate, the network disassembles the catalyst. These results open up new opportunities for controlling catalysis in synthetic chemical systems.

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Dynamic Combinatorial Discovery of a [2]-Catenane and its Guest-Induced Conversion into a Molecular Square Host

Cited by 75 publications

References 41 publications

Crystallization‐Controlled Dynamic Self‐Assembly and an On/Off Switch for Equilibration Using Boronic Ester Formation

Crystallization‐Controlled Dynamic Self‐Assembly and an On/Off Switch for Equilibration Using Boronic Ester Formation

Dynamic combinatorial synthesis of a catenane based on donor–acceptor interactions in water

Transient Substrate‐Induced Catalyst Formation in a Dynamic Molecular Network

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