Catalytic, Enantioselective Alkylation of α-Imino Esters: The Synthesis of Nonnatural α-Amino Acid Derivatives
作者:Dana Ferraris、Brandon Young、Christopher Cox、Travis Dudding、William J. Drury、Lev Ryzhkov、Andrew E. Taggi、Thomas Lectka
DOI:10.1021/ja016838j
日期:2002.1.1
Methodology for the practical synthesis of nonnatural amino acids has been developed through the catalytic, asymmetric alkylation of α-imino esters and N,O-acetals by enol silanes, ketene acetals, alkenes, and allylsilanes using chiral transition metal-phosphine complexes as catalysts (1−5 mol %). The alkylation products, which are prepared with high enantioselectivity (up to 99% ee) and diastereoselectivity
Catalytic, Asymmetric Mannich-type Reactions of <i>N</i>-Acylimino Esters: Reactivity, Diastereo- and Enantioselectivity, and Application to Synthesis of N-Acylated Amino Acid Derivatives
the synthesis of biologically important compounds were prepared using this novel catalytic asymmetricMannich-type reaction, and at the same time, absolute and relative stereochemical assignments were made. In addition, it has been revealed that alkyl vinyl ethers reacted with N-acylimino esters in the presence of a catalytic amount of the Cu(II) catalyst to give the corresponding Mannich-type adducts
在催化量的 Cu(OTf)(2)-手性二胺 3e 复合物存在下,N-酰基亚氨基酯与甲硅烷基烯醇醚反应以高产率和高对映选择性提供相应的曼尼希型加合物。各种衍生自酮的甲硅烷基烯醇醚以及酯和硫酯都能顺利反应。在α-取代的甲硅烷基烯醇醚(α-甲基或苄氧基)的反应中,以高产率和高非对映选择性和对映选择性获得了所需的顺式加合物。使用这种新型催化不对称曼尼希型反应制备了几种用于合成生物学上重要化合物的中间体,同时进行了绝对和相对立体化学分配。此外,已经表明,在催化量的 Cu(II) 催化剂存在下,烷基乙烯基醚与 N-酰基亚氨基酯反应,以高产率和高对映选择性得到相应的曼尼希型加合物。这是与烷基乙烯基醚催化不对称曼尼希型反应的第一个例子。基于Cu(II)-手性胺配合物的X射线晶体学分析、PM3计算和FT-IR分析等假设了反应机理、手性催化剂-亲电子配合物的结构以及这些催化不对称反应的过渡态. 最后,(1R,
Synthesis of diastereo- and enantiomerically pure α-amino-γ-oxo acid esters by reaction of acyliminoacetates with enamines derived from 6-membered ketones
A new efficient diastereo- and enantioselective synthesis of α-amino-γ-oxo acid esters by reaction of acyliminoacetates with enamines is described. By employing the concept of double stereodifferentiation, complete asymmetric induction (de ≧99.9%) for the C-C bond formation is obtained. Desulphurization of a sulphur containing product leads to the corresponding acyclic amino acid derivatives. The