Lithium Bromide/Triethylamine Induced Cycloaddition of N-Alkylidene 2-Amino Esters and Amides to Electron-Deficient Olefins with High Regio- and Stereoselectivity

Article abstract of DOI:10.1021/jo00242a008

The imines of 2-amino esters and amides derived from glycine, alanine, and valine are deprotonated by the action of a lithium halide and triethylamine (or DBU).The resulting anionic intermediates undergo highly regio- and stereoselective cycloadditions with a variety of olefins activated by carbonyl-type substituents to produce stereochemically defined derivatives of proline esters or amides.The scope and limitations of this novel cycloaddition are discussed.