Abstract
A novel two-stage statistical synthesis of catenanes was developed based on converting a rotaxane to a catenane. In the first stage, [2]-ωω′-bis-O-[p-(α-bromotolyl)diphenylmethyl]poly(ethylene glycol) 400-[dibenzo-58.2-crown-19.4]rotaxane was synthesized by the statistical method by mixing the “crown” polyether with poly(ethylene glycol) 400 to produce a threading equilibrium mixture at maximum concentration and blocking the hydroxyl end groups with bromomethyltrityl groups. In the second stage the rotaxane was cyclized through the α-bromotolyl end groups in very dilute solution in DMF with zinc/copper couple to yield the catenane [2]-cyclo-[1,2-diphenvlethane-p,p′-di(α-benzhydryl)poly(ethylene glycol) 400]|- [dibenzo-58.2-crown-19.4] in 14% yield. Besides the catenane, a fraction of oligorotaxane having a DP of 3 was formed by linear condensation polymerization.
Original language | English |
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Pages (from-to) | 5214-5216 |
Number of pages | 3 |
Journal | Journal of the American Chemical Society |
Volume | 98 |
Issue number | 17 |
DOIs | |
State | Published - 1 Aug 1976 |