Catalytic Asymmetric Ring-Opening of <i>meso-</i>Aziridines with Malonates under Heterodinuclear Rare Earth Metal Schiff Base Catalysis
2011-04-20T00:00:00Z (GMT) by
Catalytic asymmetric ring-opening of <i>meso</i>-aziridines with malonates is described. The combined use of two rare earth metal sources with different properties promoted the desired ring-opening reaction. A 1:1:1 mixture of a heterobimetallic La(O-<i>i</i>Pr)<sub>3</sub>/Yb(OTf)<sub>3</sub>/Schiff base <b>1a</b> (0.25−10 mol %) efficiently promoted the reaction of five-, six-, and seven-membered ring cyclic <i>meso</i>-aziridines as well as acyclic <i>meso</i>-aziridines with dimethyl, diethyl, and dibenzyl malonates, giving chiral cyclic and acyclic γ-amino esters in 99−63% yield and >99.5−97% ee.