Stereoselective Conjugate Addition of 2,3-Allenoates with Grignard Reagents

Significance

The authors describe the regio- and stereoselective addition of Grignard reagents to 2,3-allenoates to generate β,γ-unsaturated esters. This reaction proceeds with less than 5 mol% of an iron catalyst and gives the esters in high yields. This is an important contribution to synthetic chemistry in that it uses an inexpensive iron catalyst and readily available Grignard reagents.