Synfacts 2006(11): 1124-1124  
DOI: 10.1055/s-2006-949474
Synthesis of Materials and Unnatural Products
© Georg Thieme Verlag Stuttgart · New York

Macrocyclization via Ring-Emitting Covalent Fixation

Contributor(s): Timothy M. Swager, Wei Zhang
K. Adachi, H. Takasugi, Y. Tezuka*
Tokyo Institute of Technology, Japan
Further Information

Publication History

Publication Date:
24 October 2006 (online)

Significance

Replacement of the triflate counter­ions in the telechelic poly(THF) 1 with a more nucleophilic biphenyldicarboxylate by ion-exchange reaction, followed by heat treatment of complex 2 under dilution conditions (0.2 g/L), provided the covalently converted cyclic product 3 in 65% yield. The structure of 3 was confirmed by MALDI-TOF mass analysis, 1H NMR as well as SEC characterization. These results demonstrate the effective cyclization of 2 through the ring-emitting covalent conversion by the elimination of N-phenylpiperidine units at both chain ends.