Direct Asymmetric Synthesis of β-Bis-Aryl-α-Amino Acid Esters via Enantioselective Copper-Catalyzed Addition of p-Quinone Methides
Direct Asymmetric Synthesis of β-Bis-Aryl-α-Amino Acid Esters via Enantioselective Copper-Catalyzed Addition of p-Quinone Methides
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DOI：
10.1021/acscatal.5b02619
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发表时间：
2016-02-01
期刊：
影响因子：
12.9
通讯作者：
Deng, Wei-Ping
中科院分区：
文献类型：
--
作者：
He, Fu-Sheng;Jin, Jing-Hai;Deng, Wei-Ping
发展了一种高效合成带有两个相邻立体异构中心的非天然手性β-Ar，Ar ′-α-氨基酸酯的方法。在Cu（CH_3CN）（4）BF_4/Ph-Foxap催化体系（1mol%）下，首次实现了甘氨酸席夫碱与对苯醌甲基化物的1，6-共轭加成反应.该反应顺利进行，以高产率生成相应的产物，具有优异的非对映选择性（高达99：1）和对映选择性（高达> 99%ee）。随后的还原提供对映体纯的非天然氨基醇，其用于合成新的手性配体。
A highly efficient synthetic approach to unnatural chiral beta-Ar,Ar'-alpha-amino acid esters bearing two contiguous stereogenic centers has been developed. The first enantioselective 1,6-conjugate addition of glycine Schiff bases to para-quinone methides was achieved using a Cu(CH3CN)(4)BF4/Ph-Foxap catalytic system (1 mol %). The reaction proceeded smoothly to generate corresponding products in high yields with excellent diastereoselectivities (up to 99:1) and enantioselectivities (up to >99% ee). Subsequent reduction delivered enantiopure unnatural amino alcohols, which were utilized for the synthesis of novel chiral ligands.