Catalytic “Click” Rotaxanes:  A Substoichiometric Metal-Template Pathway to Mechanically Interlocked Architectures

• Published in: Journal of the American Chemical Society Vol. 128; no. 7; pp. 2186 - 2187
• Main Authors: Aucagne, Vincent, Hänni, Kevin D., Leigh, David A., Lusby, Paul J., Walker, D. Barney
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 22.02.2006; Amer Chemical Soc
• Subjects: Chemistry; Chemistry, Multidisciplinary; Exact sciences and technology; Life Sciences; Noncondensed benzenic compounds; Organic chemistry; Physical Sciences; Preparations and properties; Science & Technology; CHEMISTRY; CYCLOADDITION; AZIDES; ALKYNES; FAMILY; Organic synthesis; 1,3-Dipolar cycloaddition; Catalytic reaction; Macrocyclization; Benzenic compound; NMR spectrometry; Transition metal Complexes; Complex catalyst; Copper Complexes; Rotaxane
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/ja056903f

A route to mechanically interlocked architectures that requires only a catalytic quantity of template is described. The strategy utilizes the Cu(I)-catalyzed 1,3-cycloaddition of azides with terminal alkynes. Chelating the Cu(I) to an endotopic-binding macrocycle means that the metal atom binds to the alkyne and azide in such a way that the metal-mediated bond-forming reaction occurs through the cavity of the macrocycle, forming a rotaxane. Addition of pyridine to the reaction mixture enables the Cu(I) to turn over during the reaction, permitting substoichiometric amounts of the metal to be used. The yields are very high for a rotaxane-forming reaction (up to 94% with stoichiometric Cu(I); 82% with 20 mol % of Cu(I)), and the procedure is practically simple to do (no requirement for an inert atmosphere nor dried or distilled solvents).