Bu A,
Zhao Y,
Xiao H,
Tung C.-H,
Wu L.-Z,
Cong H.
*
Technical Institute of Physics and Chemistry, Beijing and University of Chinese Academy
of Sciences, Beijing, P. R. of China
Conjugated Covalent Template Strategy for All-Benzene Catenane Synthesis.
Angew. Chem. Int. Ed. 2022;
61: e202209449
DOI:
10.1002/anie.202209449
Key words
catenane - cycloparaphenylene - covalent template - traceless template
Significance
Syntheses and explorations of new nanocarbons with novel topology and properties have
brought new vitality to physical and chemical research. Mechanically interlocked molecules,
such as catenanes and molecular knots, are among the most challenging targets. So
far, the syntheses of these molecules mostly rely on the utilization of various covalent
and noncovalent templating motifs. In this work, the azo-group is devised to serve
as a cleavable covalent linker to facilitate the formation of two interlocked nanorings.
The most impressive achievement is the successful removal of the linker upon construction
of the catenane scaffold, rendering a traceless covalent template.
Comment
Template-assisted synthetic strategies have been demonstrated to be more effective
than the statistical threading method in attaining interlocked molecular structures.
The cleavage conditions involving SmI2 is shown to effectively overcome the steric hindrance in removing the azo-group located
in the crowded center of the catenane. The achieved all-benzene catenane
mCPP-C exhibits strong blue fluorescence with a quantum yield of 56%.
