Silver/ThioClickFerrophos-Catalyzed Enantioselective Conjugate Addition and Cycloaddition of Glycine Imino Ester with Nitroalkenes
Silver/ThioClickFerrophos-Catalyzed Enantioselective Conjugate Addition and Cycloaddition of Glycine Imino Ester with Nitroalkenes
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DOI：
10.1021/ol301916t
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发表时间：
2012-09-07
期刊：
影响因子：
5.2
通讯作者：
Fukuzawa, Shin-ichi
中科院分区：
文献类型：
--
作者：
Imae, Kazumi;Konno, Takashi;Fukuzawa, Shin-ichi
我们将AgOAc与手性二茂铁基三唑基P，S-配体ThioClickFerrophos结合用于甘氨酸亚氨基酯与硝基烯烃的反应。亚氨基甲酯的共轭加成优先产生反-α-亚氨基-γ-硝基丁酸酯，产率良好，在三乙胺存在下，在-25 ℃下，在THF中具有高达99%的高对映选择性（ee）。同时，吡咯烷环加合物作为主要产品，在良好的产率和高的对映选择性（高达96%ee），使用叔丁基亚胺酯在没有三乙胺在室温下得到。
We applied the combination of AgOAc with ThioClickFerrophos, the chiral ferrocenyl triazole-based P,S-ligand, to the reaction of glycine imino ester with nitroalkenes. The conjugate addition of the imino methyl ester preferentially produced anti-alpha-imino-gamma-nitrobutyrates in good yields with high enantioselectivities (ee) of up to 99% at -25 degrees C in THF in the presence of triethylamine. Meanwhile, the pyrrolidine cycloadducts were obtained as major products in good yields with high enantioselectivities (up to 96% ee) using tert-butyl imino ester in the absence of triethylamine at room temperature.