Catalytic asymmetric protonation of chiral calcium enolates via 1, 4-addition of malonates

…, Y Yamashita, S Kobayashi

Index: Poisson, Thomas; Yamashita, Yasuhiro; Kobayashi, Shu Journal of the American Chemical Society, 2010 , vol. 132, # 23 p. 7890 - 7892

Full Text: HTML

Citation Number: 48

Abstract

Catalytic asymmetric protonation of chiral calcium enolates was performed. Chiral calcium enolates, prepared in situ from imides and malonates via 1, 4-addition in the presence of catalytic amounts of Ca (OEt) 2, Ph-PyBox, and achiral phenol, were smoothly protonated to afford adducts bearing tertiary asymmetric carbons in high yields with high enantioselectivities. The adducts were readily converted to optically active 2-substituted 1, ...