Tetrabutylammonium-Bromide-Promoted Synthesis of Spirooxindoles through Alkyne-Aldehyde C-C Coupling and 1,3-Dipolar Cycloaddition Using Ytterbium Triflate Catalyst

摘要

Tetrabutylammonium-bromide promoted,ytterbium triflate catalyzed one-pot domino synthesis of spirooxindoles is described.The hydration-condensation of alkyne,1 aldehyde,2 C-C coupling followed by 1,3-dipolar cycloaddition of in-situ generated azomethine ylide from Isatin,3 and L-proline,4a or sarcosine,4b furnished novel spirooxindoles,5 under solventfree green-chemical conditions,in high regio and stereo selectivities and yields.The regio and stereochemistry of the synthesized derivatives were characterized by 2DNMR Spectroscopic studies.