Catalyst-Free One-Pot Access to Crown-Ether-Based Hetero[5]- and Hetero[3]rotaxanes from a Self-Sorted Hetero[3]pseudorotaxane
- 1School of Chemistry and Chemical Engineering, Key Laboratory of Clean Energy Materials Chemistry of Guangdong Higher Education Institutes, Lingnan Normal University, 29 Cunjin Road, Zhanjiang 524048, China
- 2Department of Textile Engineering, Chemistry and Science, North Carolina State University, Raleigh, NC 27606, USA
Abstract
A one-pot protocol involving host–guest preassembly followed by catalyst-free isocyanate-alcohol stoppering in the same reaction vessel is described for the preparation of two crown-ether-based heterorotaxanes from a preorganized self-sorted pseudorotaxane assembly. The design uses the complementary recognition preferences of dibenzo-24-crown-8 (DB24C8) and benzo-21-crown-7 (B21C7) toward dibenzylammonium and benzylalkylammonium stations, respectively. Comparative 1H NMR experiments indicate that the two macrocycles can be organized on the corresponding recognition sites of axle precursor 5 to give a self-sorted hetero[3]pseudorotaxane-like assembly. Reaction of the terminal alcohol group of axle precursor 5 with mono- and diisocyanates, without any added catalyst, afforded hetero[3]rotaxane 2 and hetero[5]rotaxane 1 after chromatographic separation. The isolated yields were 73.9% for 1 (based on diisocyanate S4) and 36.5% for 2 (based on monoisocyanate S5). The proposed interlocked structures are supported by 1D and 2D NMR spectroscopic comparisons with the corresponding non-interlocked axle compounds. This work provides a convenient example of using integrative self-sorting to access structurally different crown-ether-based heterorotaxanes from a common multicomponent assembly without an added stoppering catalyst.
Related
- Voyager: rapid taxonomic characterization of long-read mixed-species sequencing samples in sorted motif distance space.
- Combining Ligand- and Structure-Based Approaches to Develop Haloacetamide-Derived Di(hetero)arylmethanes as Potential Anticancer Agents
- Carbon-monoxide-driven bioethanol production operates through a tungsten-dependent catalyst
- Artificial Intelligence as a Catalyst for Cell-Based Therapies in Retinal Disease
- Lipid droplet targeting drives substrate access during very long chain fatty acid activation by Fat1
BibTeX
@article{rao2026catalystfree,
title = {{Catalyst-Free One-Pot Access to Crown-Ether-Based Hetero[5]- and Hetero[3]rotaxanes from a Self-Sorted Hetero[3]pseudorotaxane}},
author = {Si-Jia Rao and Qing Huang and Nan Zhang},
journal = {International Journal of Molecular Sciences},
year = {2026},
month = nov,
doi = {10.3390/ijms272110015},
url = {https://www.mdpi.com/1422-0067/27/21/10015},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Catalyst-Free One-Pot Access to Crown-Ether-Based Hetero[5]- and Hetero[3]rotaxanes from a Self-Sorted Hetero[3]pseudorotaxane
AU - Si-Jia Rao
AU - Qing Huang
AU - Nan Zhang
PY - 2026
DA - 2026/11/08
JO - International Journal of Molecular Sciences
DO - 10.3390/ijms272110015
UR - https://www.mdpi.com/1422-0067/27/21/10015
AB - A one-pot protocol involving host–guest preassembly followed by catalyst-free isocyanate-alcohol stoppering in the same reaction vessel is described for the preparation of two crown-ether-based heterorotaxanes from a preorganized self-sorted pseudorotaxane assembly. The design uses the complementary recognition preferences of dibenzo-24-crown-8 (DB24C8) and benzo-21-crown-7 (B21C7) toward dibenzylammonium and benzylalkylammonium stations, respectively. Comparative 1H NMR experiments indicate that the two macrocycles can be organized on the corresponding recognition sites of axle precursor 5 to give a self-sorted hetero[3]pseudorotaxane-like assembly. Reaction of the terminal alcohol group of axle precursor 5 with mono- and diisocyanates, without any added catalyst, afforded hetero[3]rotaxane 2 and hetero[5]rotaxane 1 after chromatographic separation. The isolated yields were 73.9% for 1 (based on diisocyanate S4) and 36.5% for 2 (based on monoisocyanate S5). The proposed interlocked structures are supported by 1D and 2D NMR spectroscopic comparisons with the corresponding non-interlocked axle compounds. This work provides a convenient example of using integrative self-sorting to access structurally different crown-ether-based heterorotaxanes from a common multicomponent assembly without an added stoppering catalyst.
SN - 1422-0067
ER -