Synfacts 2007(11): 1158-1158  
DOI: 10.1055/s-2007-991278
Synthesis of Materials and Unnatural Products
© Georg Thieme Verlag Stuttgart · New York

Palladium-Catalyzed Synthesis of Rotaxanes

Contributor(s): Timothy M. Swager, Ryan M. Moslin
J. Berná, J. D. Crowley, S. M. Goldup, K. D. Hänni, A.-L. Lee, D. A. Leigh*
The University of Edinburgh, UK
Further Information

Publication History

Publication Date:
23 October 2007 (online)

Significance

The authors describe a means by which to assemble rotaxanes using catalytic palladium. A catalytic amount of preformed 2 (X = Cl) undergoes transmetallation with an alkynyl cuprate. This occurs with retention of stereochemistry at Pd(II), to give trans-3, thus threading the macrocycle. Isomerization to the cis-isomer, followed by reductive elimination and dissociation liberates 4. Pd(0) is re-oxidized with iodine to the active Pd(II) species, coordination of 1 then completes the catalytic cycle.