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Updated: Jan 30, 2026

Preparation of a Corannulene-functionalized Hexahelicene by CopperI-catalyzed Alkyne-azide Cycloaddition of Nonplanar Polyaromatic Units
Published on: September 18, 2016
Functionalization of luminescent lanthanide-gallium metallacrowns using copper-catalyzed alkyne-azide cycloaddition
Jacob C Lutter1, Beatriz A Lopez Bermudez1, Tu N Nguyen1
1Willard H. Dow Laboratories, University of Michigan, 930 N. University Ave., Ann Arbor, MI, USA.
Abstract:
The synthesis and characterization of {Ln[12-MCGaIIIN(eshi)-4]}2(iph)4 and {Ln[12-MCGaIIIN(shi)-4]}2(miph)4 metallacrowns (MCs), where shi3- is salicylhydroximate, eshi3- is 4-ethynylsalicylhydroximate, iph2- is isopthalate, and miph2- is 5-maleimidoisophthalate, is reported. The ethynyl functionality allows for coupling of MCs to azides using copper(I) catalyzed alkyne-azide cycloaddition (CuAAC), while the maleimido functionality allows for coupling of the MCs to thiol-bearing compounds. We demonstrate these coupling reactions using benzyl azide for the former and cysteamine for the latter, with complete conversion shown by ESI-MS. With the Sm analogues, the MCs exhibit characteristic luminescent emission of Sm(III), which is preserved after introducing the ethynyl and maleimido groups onto the MC scaffold. Furthermore, the high stability of these compounds in solution illustrates that once functionalized, the MCs are promising for fluorescent imaging applications.
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