CHED 1576 |
| A series of spiro(indoline-2,5'-isoxazolines) and spiro(indoline-2,5'-pyrazolines) were prepared in one pot by the reaction of various nitrile oxides and nitrile imines with the dipolarophile, 2-methylene-1,3,3-trimethylindoline. Treatment of α-chloro oximes and α-chloro hydrazones with triethyl amine generates nitrile oxides and nitrile imines in situ which are then readily trapped with the aforementioned dipolarophile affording spiro(indoline-2,5'-isoxazolines) and spiro(indoline-2,5'-pyrazolines) respectively with an inherent spiro indoline moiety. These 1,3-dipolar cycloaddition reactions were highly regioselective and afforded the desired products in moderate to high yields. Along with the syntheses of these hitherto unreported spirocycles, we investigated the structural properties of “imine” versus “enamine” spiro(indoline-2,5'-pyrazolines) tautomers by X-ray crystallography and NMR. Recently, considerable effort has been paid in our research laboratory towards the synthesis of diverse spiroindole compounds in order to study their molecular properties. Acknowledgements: We thank the National Institutes of Health (NIH-RCMI: G12RR13459-07S18186 and G12RR13459) and the National Science Foundation (NSF-RISE: HRD-0734645) for their generous financial support. |
|
Research and Education in Material Science
8:00 AM-11:25 AM, Thursday, April 10, 2008 Hilton New Orleans Riverside -- HEC B, Oral
Division of Chemical Education |