Synthesis of heterocyclic molecules via room temperature decarboxylation of cyclic carbamates

CHED 488

Patrick H. Willoughby, patrick.willoughby@gmail.com1, Aaron E. May2, and Thomas R. Hoye2. (1) Department of Chemistry and Biochemistry, University of Northern Iowa, 1227 West 27th Street, Cedar Falls, IA 50614, (2) Department of Chemistry, University of Minnesota, I-4, 139 Smith Hall, 207 Pleasant St. SE, Minneapolis, MN 55455
A systematic study to determine the optimal conditions for a novel room temperature lithium iodide catalyzed decarboxylation transforming acylated oxazolidinones to oxazolines is described. Presumably iodide attack and successive decarboxylation are assisted by lithium chelation between the two carbonyl oxygen atoms of the oxazolidinone forming an iodide-containing amide. Deprotonation of the amide nitrogen leads to cyclization and formation of the oxazoline desired product. Decarboxylation was not observed for N-thioacylated oxazolidinones, thus providing evidence for the necessary chelation of a lithium cation. Optimum reaction conditions were found to include imidazole to cyclize the amide intermediate, and methylene chloride to create conditions for highest conversion. A variety of oxazoline analogues have been synthesized in high purity with moderate yield.
 

Undergraduate Research Poster Session: Organic Chemistry
11:00 AM-1:00 PM, Monday, April 7, 2008 Morial Convention Center -- Hall A, Poster

Division of Chemical Education

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008