An Approach toward the Synthesis of α-Alkylidene-β-amino Esters

Significance

The authors have previously reported the three-component coupling of α,β-acetylenic esters, aldehydes, and trimethylsilyl iodide using chiral cationic oxazaborolidinium catalysts, providing optically active Morita-Baylis-Hillman adducts with good yield and selectivity. In the present report they demonstrate the utility of these products in the synthesis of α-alkylidene-β-amino esters via a thermal Overman rearrangement. The resulting products are useful intermediates for the synthesis of non-natural amino acids and other pharmaceutically active targets.