Enantiocontrolled Synthesis of β‐Branched α‐Amino Acids by Using Cu
<sup>I</sup>
‐Catalyzed 1,4‐Addition of Glycine Imines to β‐Substituted
<i>gem</i>
‐Diactivated Olefins
作者:Jorge Hernández‐Toribio、Ramón Gómez Arrayás、Juan C. Carretero
DOI:10.1002/chem.201100374
日期:2011.5.27
Branching out! The catalytic asymmetric conjugate addition of glycinate Schiff bases to β‐substituted gem‐diactivated Michael acceptors under proton transfer conditions gives a variety of β‐branched α‐amino acids (see scheme; Dpm=diphenylmethylene, EWG=electron‐withdrawing group) with excellent levels of diastereo‐ (typically syn/anti >90:10) and enantiocontrol (90–99 % ee).
分支出!催化不对称共轭加成的甘氨酸Schiff碱至β -取代的宝石-diactivated质子转移条件下迈克尔受体给出的各种β-α支链氨基酸(参见方案; DPM =二苯基亚甲基,EWG =吸电子基团)具有优良的非对映体水平(通常是syn / anti > 90:10)和对映体控制(90–99% ee)。