Dedicated to Professor Scott E. Denmark

Published as part of the Special Section dedicated to Scott E. Denmark on the occasion of his 65^th birthday

Abstract

Substituents at Cγ of proline are valuable probes to tune the trans/cis ratio of Xaa–Pro bonds. We investigated the effect of Cγ-substituents on the reactivity and stereoselectivity of the peptidic catalyst H-dPro-Pro-Glu-NH₂. Derivatives that bear electron-withdrawing and -donating substituents (OH, F, N₃, and SMe) at Cγ of the middle Pro-residue were examined. The results show that substituents at a 4R-configured Cγ hardly affect the stereoselectivity of the peptidic catalyst whereas substituents at a 4S-configured Cγ can be used to tune and improve the catalytic performance.

Substituents at Cγ of proline are valuable probes to tune the trans/cis ratio of Xaa–Pro bonds. We investigated the effect of Cγ-substituents on the reactivity and stereoselectivity of the peptidic catalyst H-dPro-Pro-Glu-NH₂. Derivatives that bear electron-withdrawing and -donating substituents (OH, F, N₃, and SMe) at Cγ of the middle Pro-residue were examined. The results show that substituents at a 4R-configured Cγ hardly affect the stereoselectivity of the peptidic catalyst whereas substituents at a 4S-configured Cγ can be used to tune and improve the catalytic performance.

中文翻译：

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γ取代的脯氨酸衍生物对肽催化剂H-dPro-Pro-Glu-NH2性能的影响

献给Scott E.Denmark教授

发布时间作为的一部分奉献给斯科特E.丹麦在他65之际特科^次生日

抽象的

脯氨酸Cγ处的取代基是用于调节Xaa–Pro键的反式/顺式比的有价值的探针。我们研究了Cγ-取代基对肽催化剂H - d Pro-Pro-Glu-NH ₂的反应性和立体选择性的影响。考察了在中间残基的Cγ处带有吸电子和供电子取代基（OH，F，N ₃和SMe）的衍生物。结果表明，在4 R构型的Cγ处的取代基几乎不影响肽催化剂的立体选择性，而在4 S构型的Cγ处的取代基可用于调节和改善催化性能。

脯氨酸Cγ处的取代基是用于调节Xaa–Pro键的反式/顺式比的有价值的探针。我们研究了Cγ-取代基对肽催化剂H - d Pro-Pro-Glu-NH ₂的反应性和立体选择性的影响。考察了在中间残基的Cγ处带有吸电子和供电子取代基（OH，F，N ₃和SMe）的衍生物。结果表明，在4 R构型的Cγ处的取代基几乎不影响肽催化剂的立体选择性，而在4 S构型的Cγ处的取代基可用于调节和改善催化性能。