1,720,965 research outputs found
Active template synthesis of chiral interlocked molecules
No full textMechanically interlocked molecules are very interesting compounds for their architecture. The core of these molecules is readily accessible using a large range of synthetic approaches that give access to a wide range of functional group for applications such as sensors, molecular machines or catalyst. This last field attracts attention with the recent emergence of enantioselective catalytic platform and tuneable catalysts, such as on and off switchable or stimuli response catalysts.In this thesis, the starting chapter highlights the evolution of the synthesis of mechanically interlocked molecules and a selection of chiral systems with recent applications in enantioselective transformations. The following chapter illustrates the influence of the mechanical bond in copper-catalysed transformations. This involved the synthesis of a model rotaxane and the application of rotaxane-based ligand in various copper-catalysed transformations with improvement in terms of diastereoselectivity and conversion. The third chapter is an illustration of a modification of reactivity related to the mechanical bond. The unprecedented tandem reaction, of an otherwise stable moiety, for the synthesis of rotaxanes highlighted in this chapter was a feature of the mechanical bond. The fourth chapter is dedicated to the improvement of an existing approach for the production of simple catenanes in excellent yield. The approach developed in this chapter was extended to multicomponent systems with unprecedented success. The last chapter in an extension of the fourth chapter to access chiral catenanes. The development of a new approach for the accessible synthesis of topologically chiral catenanes enabled the access of usually very complicated molecules
Characterisation data for An Auxiliary Approach for the Stereoselective Synthesis of Topologically Chiral Catenanes
No full textNMR, CD, HPLC, MS data for novel compounds reported in: Goldup, S. M., Denis, M., Modicom, F., & Lewis, J. E. M. (2019). An auxiliary approach for the stereoselective synthesis of topologically chiral catenanes. Chem, 5(6), 1512-1520. https://doi.org/10.1016/j.chempr.2019.03.008</span
Data for Chemical Consequences of the Mechanical Bond
No full textCharacterisation data for novel compounds reported and mechanistic studies
This file contains the data from Chemical Consequences of the Mechanical Bond: A Tandem Active Template‐Rearrangement Reaction (DOI:10.1002/anie.201813950). In the folders can be found the characterisation data for the compounds reported. In addition, MS and NMR data is provided for the mechanistic studies and XYZ coordinates are provided for the modelling study.</span
An auxiliary approach for the stereoselective synthesis of topologically Chiral catenanes
Full text linkCatenanes, molecules in which two rings are threaded through one another like links in a chain, can form as two structures related as object and mirror image but otherwise identical if the individual rings lack bilateral symmetry. These structuresare described as “topologically chiral” as, unlike most chiral molecules,it is not possible to convert onemirror-image formto the other undertherules of mathematical topology. Although intriguing, and discussed as early as 1961, to date all methods to access molecules containing only this topological stereogenic element requiretheseparation ofthe mirror imageforms using chiral stationary phase high performance liquid chromatography (PCSP-HPLC)which has limited their investigation to date. Here we present a simple method that uses a readily available source of chiral information to allow the stereoselective synthesis of topologically chiral catenanes
A co-conformationally “topologically” chiral catenane
No full textCatenanes composed of two achiral rings that are oriented (Cnh symmetry) because of the sequence of atoms they contain are referred to as topologically chiral. Here we present the synthesis of a highly enantioenriched catenane containing a related but overlooked “co-conformationally ‘topologically’ chiral” stereo-genic unit, which arises when a bilaterally symmetric Cnv ring is desymmetrised by the position of an oriented macrocycle
Dataset for Stereoselective Synthesis of Mechanically Planar Chiral Rotaxanes
No full textRaw data including NMR and CD spectra for:
Jinks, M. et al (2018). Stereoselective synthesis of mechanically planar chiral rotaxanes. Angewandte Chemie International Edition. </span
Efficient multi-component active template synthesis of catenanes
Full text linkWe describe a simple and high yielding active template synthesis of [2]catenanes. In addition to mechanical bond formation using a single pre-macrocycle bearing an azide and alkyne moiety, our method is also suitable for the co-macrocyclisation of readily available bis-alkyne and bis-azide co-monomers and even short alkyne/azide components which oligomerise prior to mechanical bond formation
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Chemical consequences of the mechanical bond: a tandem active template-rearrangement reaction
No full textWe report the unexpected discovery of a tandem active template CuAAC‐rearrangement process in which N2 is extruded en route to the 1,2,3‐triazole product to give instead acrylamide rotaxanes. Mechanistic investigations suggest this process is dictated by the mechanical bond, which stabilizes the CuI‐triazolide intermediate of the CuAAC reaction and diverts it down the rearrangement pathway; when no mechanical bond is formed, the CuAAC product is isolated
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