A Facile Cu(I)/TF-BiphamPhos-Catalyzed Asymmetric Approach to Unnatural α-Amino Acid Derivatives Containing <i>gem</i>-Bisphosphonates
作者:Zhi-Yong Xue、Qing-Hua Li、Hai-Yan Tao、Chun-Jiang Wang
DOI:10.1021/ja2043563
日期:2011.8.3
A novel catalyticasymmetricMichaeladdition of azomethine ylide with β-substituted alkylidene bisphosphates was realized in the presence of a chiral copper(I)/TF-BiphamPhos complex. The present system provides a unique and facile access to enantioenriched unnatural α-amino acid derivatives containing gem-bisphosphonates (gem-BPs) in high yields with excellent diastereoselectivities and enantioselectivities
在手性铜 (I)/TF-BiphamPhos 配合物存在下,实现了一种新型催化不对称迈克尔加成与 β-取代的亚烷基双磷酸盐的偶氮甲碱叶立德。本系统提供了一种独特且简便的途径,可以高产率地获得富含对映体的非天然 α-氨基酸衍生物,其中含有 gem-双膦酸盐 (gem-BPs),具有出色的非对映选择性和对映选择性。随后的转化可以方便地制备含有 BP 和双膦酸的生物活性非天然 α-氨基酸衍生物,而不会损失非对映体和对映体过量。
Efficient diastereo- and enantioselective synthesis of α,β-disubstituted γ-phosphono sulfonates
The first asymmetric synthesis of alpha,beta-disubstituted gamma-phosphono sulfonates is reported. The key step is the Michael addition of a lithiated enantiopure sulfonate bearing an inexpensive chiral sugar auxiliary to alpha,beta-unsaturated phosphonates in good diastereoselectivities. After chromatographic purification, the cleavage of the chiral sugar auxiliary proceeds without any epimerization or racemization to form the corresponding isopropyl sulfonate in very good overall yield (75%) and excellent diastereomeric and enantiomeric excess (de, ee >= 95%). (C) 2009 Elsevier Ltd. All rights reserved.
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