Copper-mediated Michael addition of ethyl bromodifluoroacetate to N-protected α,β-unsaturated α-amino acid esters was applied for straightforward synthesis of γ,γ-difluorinated analogues of glutamic acid (compound 1) and glutamine (compound 10). Moreover, a proline-based, sterically constrained analog of γ,γ-difluoroglutamic acid (compound 24) was prepared.

中文翻译：

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通过将溴代二氟乙酸乙酯加成到α，β-不饱和α-氨基酸衍生物上来直接合成氟化氨基酸

铜介导的溴代二氟乙酸乙酯向N保护的α，β-不饱和α-氨基酸酯的迈克尔加成反应用于直接合成谷氨酸（化合物1）和谷氨酰胺（化合物10）的γ，γ-二氟类似物。此外，制备了基于脯氨酸的，空间受限的γ，γ-二氟谷氨酸类似物（化合物24）。