An Asymmetric, Bifunctional Catalytic Approach to Non-Natural α-Amino Acid Derivatives
作者:Daniel H. Paull、Ethan Alden-Danforth、Jamison Wolfer、Cajetan Dogo-Isonagie、Ciby J. Abraham、Thomas Lectka
DOI:10.1021/jo070472x
日期:2007.7.1
A catalytic, asymmetric process for the synthesis of 1,4-benzoxazinones from o-benzoquinone imides and ketene enolates is reported. Addition of Lewis acids (Zn(OTf)2, In(OTf)3, and in particular Sc(OTf)3) creates a bifunctional catalytic system that dramatically increases the reaction rate and the yield of these non-natural amino acid precursors while preserving the remarkable enantioselectivity inherent
据报道,由邻苯醌醌和乙烯酮烯醇酸酯合成1,4-苯并恶嗪酮的催化,不对称过程。添加路易斯酸(Zn(OTf)2,In(OTf)3,特别是Sc(OTf)3)会产生双功能催化系统,该系统可以显着提高反应速度和这些非天然氨基酸前体的收率,同时保留反应固有的显着对映选择性。助催化剂Sc(OTf)3最多可将产率提高42%,而生产ee> 99%的产品。