Stepwise, Protecting Group Free Synthesis of Rotaxanes
AbstractDespite significant advances in the last three decades towards high yielding syntheses of rotaxanes, the preparation of systems constructed from more than two components remains a challenge. Herein we build upon our previous report of an active template copper-catalyzed azide-alkyne cycloaddition (CuAAC) rotaxane synthesis with a diyne in which, following the formation of the first mechanical bond, the steric bulk of the macrocycle tempers the reactivity of the second alkyne unit. We have now extended this approach to the use of 1,3,5-triethynylbenzene in order to successively prepare -, - and rotaxanes without the need for protecting group chemistry. Whilst the first two iterations proceeded in good yield, the steric shielding that affords this selectivity also significantly reduces the efficacy of the active template (AT)-CuAAC reaction of the third alkyne towards the preparation of rotaxanes, resulting in severely diminished yields. View Full-Text
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Lewis, J.E.M.; Winn, J.; Goldup, S.M. Stepwise, Protecting Group Free Synthesis of Rotaxanes. Molecules 2017, 22, 89.
Lewis JEM, Winn J, Goldup SM. Stepwise, Protecting Group Free Synthesis of Rotaxanes. Molecules. 2017; 22(1):89.Chicago/Turabian Style
Lewis, James E.M.; Winn, Joby; Goldup, Stephen M. 2017. "Stepwise, Protecting Group Free Synthesis of Rotaxanes." Molecules 22, no. 1: 89.
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