Synfacts 2007(1): 0037-0037  
DOI: 10.1055/s-2006-955680
Synthesis of Materials and Unnatural Products
© Georg Thieme Verlag Stuttgart · New York

A Reusable Ring-Enlarging Catalyst

Contributor(s): Timothy M. Swager, Yong Yang
M. H. Chisholm*, J. C. Gallucci, H. Yin
Ohio State University, Columbus, USA
Further Information

Publication History

Publication Date:
15 December 2006 (online)

Significance

A polymer-supported catalyst is generated by adding excess n-BuLi to a benzene suspension of amine-functionalized polystyrene beads. The catalysis is active in enlarging the rings of lactides and 2,5-morpholinediones, leading to a series of cyclic oligoesters and cyclodepsipeptides, respectively. NaBPh4 is shown to effectively sequester the 18-membered rings due to the complexation of the Na+ ions with the suitable-sized rings. The authors also investigate other metallated supports derived from Me2Mg and Et2Zn but they are shown to be less reactive than the lithiated support.