Related Experiment Video
Updated: Jun 14, 2026
![Solid-phase Synthesis of [4.4] Spirocyclic Oximes](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F58508.jpg&w=3840&q=50)
Solid-phase Synthesis of [4.4] Spirocyclic Oximes
Published on: February 6, 2019
Efficient synthesis of a hetero[4]rotaxane by a "threading-stoppering-followed-by-clipping" approach
Jun Yin1, Chunyan Chi, Jishan Wu
1Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543.
Abstract:
A "threading-stoppering-followed-by-clipping" approach was used for the synthesis of a hetero[4]rotaxane, in which one cucurbit[6]uril (CB[6]) and two hetero crown ether macrocycles are threaded onto one dumbbell-shaped molecule. The process involves three steps: (1) threading of a CB[6] macrocycle onto a thread containing two dialkylammonium sites to form a CB[6]-based pseudo[2]rotaxane; (2) stoppering of the as-formed pseudo[2]rotaxane by imine condensation reaction followed by reduction/protonation to afford a CB[6]-based [2]rotaxane with two new dialkylammonium sites; and (3) selective clipping of two hetero crown ether macrocycles onto the newly-formed ammonium sites and subsequent reduction of the imine bonds in each crown ether to afford the final hetero[4]rotaxane in good yield. The whole process was followed by NMR spectroscopy and the structure of the hetero[4]rotaxane was confirmed by NMR spectroscopy, elemental analysis and mass spectrometry.
More Related Videos
10:17Efficient Construction of Drug-like Bispirocyclic Scaffolds Via Organocatalytic Cycloadditions of α-Imino γ-Lactones and Alkylidene Pyrazolones
Published on: February 7, 2019
09:35Preparation of a Corannulene-functionalized Hexahelicene by Copper(I)-catalyzed Alkyne-azide Cycloaddition of Nonplanar Polyaromatic Units
Published on: September 18, 2016
Related Concept Videos
Olefin Metathesis Polymerization: Ring-Opening Metathesis Polymerization (ROMP)
Olefin Metathesis Polymerization: Overview
Ruthenium-based Grubbs catalyst is the most commonly used catalyst for olefin metathesis polymerization. Grubbs catalyst consists of a...
Thermal Electrocyclic Reactions: Stereochemistry
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction
Cycloaddition Reactions: Overview
Ziegler–Natta Chain-Growth Polymerization: Overview