Catalytic Asymmetric Protonation of Chiral Calcium Enolates via 1,4-Addition of Malonates
作者:Thomas Poisson、Yasuhiro Yamashita、Shu̅ Kobayashi
DOI:10.1021/ja102555a
日期:2010.6.16
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
进行了手性烯醇钙的催化不对称质子化。在催化量的 Ca(OEt)(2)、Ph-PyBox 和非手性苯酚存在下,由酰亚胺和丙二酸通过 1,4-加成原位制备的手性烯醇钙被顺利质子化以提供带有叔不对称碳的加合物高产率和高对映选择性。加合物很容易转化为光学活性的 2-取代 1,5-二羧酸衍生物。