title: A one-pot synthesis of constitutionally unsymmetrical rotaxanes using sequential Cu(I)-catalyzed azide-alkyne cycloadditions.
abstract: A one-pot sequential Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC) strategy is presented for the synthesis of constitutionally unsymmetrical cyclobis(paraquat-p-phenylene)-based rotaxanes in good yields from simple starting materials. The methodology consists of performing multiple CuAAC reactions to stopper a pseudorotaxane in a stepwise manner, the order of which is controlled through silyl-protection and Ag(I)-catalyzed deprotection of a terminal alkyne. The methodology is highlighted by the synthesis of an amphiphilic branched [4]rotaxane. The methodology increases the ability to access ever more complicated mechanically interlocked compounds to serve in devices as sophisticated and functional molecular machinery.
authors.affiliation: The California NanoSystems Institute and Department of Chemistry and Biochemistry, University of California, Los Angeles, 405 Hilgard Avenue, Los Angeles, CA 90095, USA.
authors.forename: Jason M
authors.initials: JM
authors.lastname: Spruell
authors.forename: William R
authors.initials: WR
authors.lastname: Dichtel
authors.forename: James R
authors.initials: JR
authors.lastname: Heath
authors.forename: J Fraser
authors.initials: JF
authors.lastname: Stoddart