1
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Goldup SM. The End of the Beginning of Mechanical Stereochemistry. Acc Chem Res 2024; 57:1696-1708. [PMID: 38830116 PMCID: PMC11191403 DOI: 10.1021/acs.accounts.4c00195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 04/29/2024] [Accepted: 05/01/2024] [Indexed: 06/05/2024]
Abstract
ConspectusStereochemistry has played a key role in the development of synthetic chemistry for the simple reason that the function and properties of most molecules, from medicine to materials science, depend on their shape and thus the stereoisomer used. However, despite the potential for rotaxanes and catenanes to display unusual forms of stereochemistry being identified as early as 1961, this aspect of the mechanical bond remained underexplored and underexploited; until 2014 it was only possible to access chiral rotaxanes and catenanes whose stereoisomerism is solely attributable to the mechanical bond using chiral stationary phase high performance liquid chromatography, which limited their production on scale and thus inhibited the investigation of their properties and applications. Furthermore, the stereogenic units of such molecules and analogues were often poorly described, which made it hard to fully articulate both what had been achieved in the field and what problems were left to solve. Relatively recently, methods to access rotaxanes and catenanes that display mechanical stereochemistry selectively have been developed, making these intriguing structures available for study in a range of prototypical applications including catalysis, sensing, and as chiral luminophores.In this Account, we briefly discuss the history of mechanical stereochemistry, beginning in 1961 when the potential for mechanical stereoisomerism was first identified, before defining how mechanical stereochemistry arises from a structural point of view. Building on this, using simple stereochemical arguments, we confirm that the complete set of unique stereogenic units of two-component rotaxanes and catenanes have finally been identified and categorized unambiguously, with the last being identified only in 2024. After pausing to discuss some of the stereochemical curiosities that arise when molecules contain both covalent and mechanical stereogenic units, and the potential for stereoisomerism to arise due to co-conformational movement, we use our stereochemical framework to summarize our efforts to develop conceptually general approaches to [2]catenanes and [2]rotaxanes containing all of the possible mechanical stereogenic units. In particular, we highlight how the nature of a mechanical stereogenic unit affects the available strategies for their stereoselective synthesis. We finish by highlighting recent prototypical chemical applications of interlocked molecules that rely on their mechanical stereochemistry, before discussing future directions and challenges.Taken together, we propose that the transition of such molecules from being hard to make and poorly described, to being available in high stereopurity using clearly articulated methodological and stereochemical concepts suggests that the field is finally maturing. Thus, we are now coming to the end of the beginning of mechanical stereochemistry. The stage is now set for such molecules to play a functional role in a range of areas, indeed in any chemical or physical application where control over molecular shape is required.
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Affiliation(s)
- Stephen M. Goldup
- School of Chemistry, University
of Birmingham, Birmingham B15 2TT, U.K.
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2
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Gallagher P, Savoini A, Saady A, Maynard JRJ, Butler PWV, Tizzard GJ, Goldup SM. Facial Selectivity in Mechanical Bond Formation: Axially Chiral Enantiomers and Geometric Isomers from a Simple Prochiral Macrocycle. J Am Chem Soc 2024; 146:9134-9141. [PMID: 38507717 PMCID: PMC10996000 DOI: 10.1021/jacs.3c14329] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 02/12/2024] [Accepted: 02/14/2024] [Indexed: 03/22/2024]
Abstract
In 1971, Schill recognized that a prochiral macrocycle encircling an oriented axle led to geometric isomerism in rotaxanes. More recently, we identified an overlooked chiral stereogenic unit in rotaxanes that arises when a prochiral macrocycle encircles a prochiral axle. Here, we show that both stereogenic units can be accessed using equivalent strategies, with a single weak stereodifferentiating interaction sufficient for moderate to excellent stereoselectivity. Using this understanding, we demonstrated the first direct enantioselective (70% ee) synthesis of a mechanically axially chiral rotaxane.
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Affiliation(s)
- Peter
R. Gallagher
- Chemistry, University of Southampton, University Road, Southampton, SO17 1BJ, U.K.
- School
of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, U.K.
| | - Andrea Savoini
- Chemistry, University of Southampton, University Road, Southampton, SO17 1BJ, U.K.
- School
of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, U.K.
| | - Abed Saady
- Chemistry, University of Southampton, University Road, Southampton, SO17 1BJ, U.K.
- School
of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, U.K.
| | - John R. J. Maynard
- Chemistry, University of Southampton, University Road, Southampton, SO17 1BJ, U.K.
| | - Patrick W. V. Butler
- Chemistry, University of Southampton, University Road, Southampton, SO17 1BJ, U.K.
| | - Graham J. Tizzard
- Chemistry, University of Southampton, University Road, Southampton, SO17 1BJ, U.K.
| | - Stephen M. Goldup
- Chemistry, University of Southampton, University Road, Southampton, SO17 1BJ, U.K.
- School
of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, U.K.
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3
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Savoini A, Gallagher PR, Saady A, Goldup SM. The Final Stereogenic Unit of [2]Rotaxanes: Type 2 Geometric Isomers. J Am Chem Soc 2024; 146:8472-8479. [PMID: 38499387 PMCID: PMC10979452 DOI: 10.1021/jacs.3c14594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 02/12/2024] [Accepted: 02/14/2024] [Indexed: 03/20/2024]
Abstract
Mechanical stereochemistry arises when the interlocking of stereochemically trivial covalent subcomponents results in a stereochemically complex object. Although this general concept was identified in 1961, the stereochemical description of these molecules is still under development to the extent that new forms of mechanical stereochemistry are still being identified. Here, we present a simple analysis of rotaxane and catenane stereochemistry that allowed us to identify the final missing simple mechanical stereogenic unit, an overlooked form of rotaxane geometric isomerism, and demonstrate its stereoselective synthesis.
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Affiliation(s)
- Andrea Savoini
- School
of Chemistry, University of Southampton, University Road, Southampton SO17 1BJ, U.K.
- School
of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, U.K.
| | - Peter R. Gallagher
- School
of Chemistry, University of Southampton, University Road, Southampton SO17 1BJ, U.K.
- School
of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, U.K.
| | - Abed Saady
- School
of Chemistry, University of Southampton, University Road, Southampton SO17 1BJ, U.K.
- School
of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, U.K.
| | - Stephen M. Goldup
- School
of Chemistry, University of Southampton, University Road, Southampton SO17 1BJ, U.K.
- School
of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, U.K.
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4
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Cester Bonati F, Bazzoni M, Baccini C, Zanichelli V, Orlandini G, Arduini A, Cera G, Secchi A. Calix[6]arene-Based [3]Rotaxanes as Prototypes for the Template Synthesis of Molecular Capsules. MOLECULES (BASEL, SWITZERLAND) 2023; 28:molecules28020595. [PMID: 36677647 PMCID: PMC9864859 DOI: 10.3390/molecules28020595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 12/24/2022] [Accepted: 01/01/2023] [Indexed: 01/11/2023]
Abstract
In this work, the ability of several bis-viologen axles to thread a series of heteroditopic tris(N-phenylureido)calix[6]arene wheels to give interwoven supramolecular complexes to the [3]pseudorotaxane type was studied. The unidirectionality of the threading process inside these nonsymmetric wheels allows the formation of highly preorganised [3]pseudorotaxane and [3]rotaxane species in which the macrocycles phenylureido moieties, functionalised with either ester, carboxylic, or hydroxymethyl groups, are facing each other. As verified by NMR and semiempirical computational studies, these latter compounds possess the correct spatial arrangement of their subcomponents, which could lead, in principle, upon proper bridging reaction, to the realisation of upper-to-upper molecular capsules that are based on calix[6]arene derivatives.
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5
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Bazzoni M, Andreoni L, Silvi S, Credi A, Cera G, Secchi A, Arduini A. Selective access to constitutionally identical, orientationally isomeric calix[6]arene-based [3]rotaxanes by an active template approach. Chem Sci 2021; 12:6419-6428. [PMID: 34084442 PMCID: PMC8115267 DOI: 10.1039/d1sc00279a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Tris(phenylureido)calix[6]arene is endowed with unique properties that make it a valuable macrocyclic component for the synthesis of mechanically interlocked molecules. Its three-dimensional and intrinsically nonsymmetric structure is kinetically selective toward two processes: (i) in apolar media, the threading of bipyridinium based axle-like components takes place exclusively from the upper rim; (ii) SN2 alkylation reactions of a pyridylpyridinium precursor engulfed in the cavity occur selectively at pyridylpyridinium nitrogen atom located at the macrocycle upper rim (active template synthesis). Here we exploit such properties to prepare two series of [3]rotaxanes, each consisting of three sequence isomers that arise from the threading of two identical but nonsymmetric wheels on a symmetric thread differing only for the reciprocal orientation of the macrocycles. The features of the calix[6]arene and the active template synthetic approach, together with a careful selection of the precursors, enabled us to selectively synthesise the [3]rotaxane sequence isomers of each series with fast kinetics and high yields. Expedient access to a series of spatially controlled oriented [3]rotaxane isomers via a metal-free active template approach.![]()
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Affiliation(s)
- Margherita Bazzoni
- Dipartimento di Scienze Chimiche, della Vita e della Sostenibilità Ambientale, Università di Parma Parco Area delle Scienze 17/A I-43124 Parma Italy
| | - Leonardo Andreoni
- Dipartimento di Chimica "G. Ciamician", Università di Bologna Via Selmi 2 I-40126 Bologna Italy
| | - Serena Silvi
- Dipartimento di Chimica "G. Ciamician", Università di Bologna Via Selmi 2 I-40126 Bologna Italy
| | - Alberto Credi
- Istituto per la Sintesi Organica e la Fotoreattività, Consiglio Nazionale delle Ricerche Via Gobetti 101 I-40129 Bologna Italy.,Dipartimento di Chimica Industriale "Toso Montanari", Università di Bologna Viale del Risorgimento 4 I-40136 Bologna Italy
| | - Gianpiero Cera
- Dipartimento di Scienze Chimiche, della Vita e della Sostenibilità Ambientale, Università di Parma Parco Area delle Scienze 17/A I-43124 Parma Italy
| | - Andrea Secchi
- Dipartimento di Scienze Chimiche, della Vita e della Sostenibilità Ambientale, Università di Parma Parco Area delle Scienze 17/A I-43124 Parma Italy
| | - Arturo Arduini
- Dipartimento di Scienze Chimiche, della Vita e della Sostenibilità Ambientale, Università di Parma Parco Area delle Scienze 17/A I-43124 Parma Italy
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6
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Cera G, Arduini A, Secchi A, Credi A, Silvi S. Heteroditopic Calix[6]arene Based Intervowen and Interlocked Molecular Devices. CHEM REC 2021; 21:1161-1181. [PMID: 33656250 DOI: 10.1002/tcr.202100012] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 02/17/2021] [Indexed: 01/13/2023]
Abstract
Since the dawn of supramolecular chemistry, calixarenes have been employed as platforms onto which functional groups and binding sites can be loaded in a regio- and stereocontrolled manner for the recognition of charged and neutral species. Despite their wider annulus, potentially suitable to bind larger guests, the larger members of the calixarene series have been relatively less employed, mainly because of the synthetic difficulties to control their conformational flexibility and their regioselective functionalization. In this account, we will present the achievements gained during the last two decades on the use of the calix[6]arene as a platform to build-up structures in which the macrocycle acts as a wheel for the synthesis of oriented (pseudo)rotaxanes. We also account on how these calix[6]arene hosts affect the reactivity or spectroscopic properties of their bound guests.
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Affiliation(s)
- Gianpiero Cera
- Dipartimento di Scienze Chimiche, della Vita e della Sostenibilità Ambientale, Università di Parma, Parco Area delle Scienze 17/A, I-43124, Parma, Italy
| | - Arturo Arduini
- Dipartimento di Scienze Chimiche, della Vita e della Sostenibilità Ambientale, Università di Parma, Parco Area delle Scienze 17/A, I-43124, Parma, Italy
| | - Andrea Secchi
- Dipartimento di Scienze Chimiche, della Vita e della Sostenibilità Ambientale, Università di Parma, Parco Area delle Scienze 17/A, I-43124, Parma, Italy
| | - Alberto Credi
- Dipartimento di Chimica Industriale "Toso Montanari", Viale del Risorgimento 4, I-40136, Bologna, Italy.,Istituto per la Sintesi Organica e la Foto reattività, Consiglio Nazionale delle Ricerche, via Gobetti 101, 40129, Bologna, Italy
| | - Serena Silvi
- Dipartimento di Chimica "G. Ciamician", Università di Bologna, Via Selmi 2, I-40126, Bologna, Italy
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7
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Kashapov RR, Razuvayeva YS, Ziganshina AY, Mukhitova RK, Sapunova AS, Voloshina AD, Nizameev IR, Kadirov MK, Zakharova LY. Design of N-Methyl-d-Glucamine-Based Resorcin[4]arene Nanoparticles for Enhanced Apoptosis Effects. Mol Pharm 2020; 17:40-49. [PMID: 31746611 DOI: 10.1021/acs.molpharmaceut.9b00599] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The addition of specific chemical groups in a macrocycle structure influences its functional properties and, consequently, can provide new possibilities, among which are aggregation properties, water solubility, biocompatibility, stimuli response, biological activity, etc. Herein, we report synthesis of new resorcin[4]arene with N-methyl-d-glucamine groups on the upper rim and n-decyl chains on the lower rim, an investigation of its self-assembly behavior in aqueous media, and its use as a building block for the formation of drug nanocontainer. N-methyl-d-glucamine fragments in the resorcin[4]arene structure promote higher stability in solutions, simplification of self-aggregation, and increased biological activity. Antimicrobial and hemolytic activity assessment revealed that this resorcin[4]arene obtained is nontoxic. The study of cell penetration was carried out with both free and encapsulated doxorubicin (DOX). Surprisingly, DOX-loaded macrocycle aggregates are more efficient in causing apoptosis in human cancer cell line. Conceivably, this knowledge will help in the rational design of DOX combination for novel drug-administration strategies in cancer treatment.
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Affiliation(s)
- Ruslan R Kashapov
- Arbuzov Institute of Organic and Physical Chemistry , FRC Kazan Scientific Center of RAS , 8 Arbuzov str. , Kazan 420088 , Russia
| | - Yuliya S Razuvayeva
- Arbuzov Institute of Organic and Physical Chemistry , FRC Kazan Scientific Center of RAS , 8 Arbuzov str. , Kazan 420088 , Russia.,Kazan National Research Technological University , 68 K. Marx str. , Kazan 420015 , Russia
| | - Albina Y Ziganshina
- Arbuzov Institute of Organic and Physical Chemistry , FRC Kazan Scientific Center of RAS , 8 Arbuzov str. , Kazan 420088 , Russia
| | - Rezeda K Mukhitova
- Arbuzov Institute of Organic and Physical Chemistry , FRC Kazan Scientific Center of RAS , 8 Arbuzov str. , Kazan 420088 , Russia
| | - Anastasiya S Sapunova
- Arbuzov Institute of Organic and Physical Chemistry , FRC Kazan Scientific Center of RAS , 8 Arbuzov str. , Kazan 420088 , Russia
| | - Alexandra D Voloshina
- Arbuzov Institute of Organic and Physical Chemistry , FRC Kazan Scientific Center of RAS , 8 Arbuzov str. , Kazan 420088 , Russia
| | - Irek R Nizameev
- Arbuzov Institute of Organic and Physical Chemistry , FRC Kazan Scientific Center of RAS , 8 Arbuzov str. , Kazan 420088 , Russia.,Kazan National Research Technological University , 68 K. Marx str. , Kazan 420015 , Russia
| | - Marsil K Kadirov
- Arbuzov Institute of Organic and Physical Chemistry , FRC Kazan Scientific Center of RAS , 8 Arbuzov str. , Kazan 420088 , Russia.,Kazan National Research Technological University , 68 K. Marx str. , Kazan 420015 , Russia
| | - Lucia Ya Zakharova
- Arbuzov Institute of Organic and Physical Chemistry , FRC Kazan Scientific Center of RAS , 8 Arbuzov str. , Kazan 420088 , Russia.,Kazan National Research Technological University , 68 K. Marx str. , Kazan 420015 , Russia
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8
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Herndon JW. The chemistry of the carbon-transition metal double and triple bond: Annual survey covering the year 2018. Coord Chem Rev 2019. [DOI: 10.1016/j.ccr.2019.213051] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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