Lanthanoid Triflate Catalyzed Conjugate Addition of Amines to α, β-Unsaturated Esters. A Facile Route to Optically Active β-Lactam

Catalytic amount of lanthanoid(III) triflates promoted the conjugate addition of amines to 2-alkenoic acid esters to give β-amino esters. The reaction of benzylamine with α,β-unsaturated esters containing a stereogenic center at γ-position proceeded diastereoselectivity to yield optically active β-lactam precursors.