Asymmetric Reduction of Lactam-Based β-Aminoacrylates. Synthesis of Heterocyclic β2-Amino Acids

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• 作者：Hugo Rego Campello ; Jeremy Parker ; Matthew Perry ; Per Ryberg ; Timothy Gallagher
• 刊名：Organic Letters
• 出版年：2016
• 出版时间：August 19, 2016
• 年：2016
• 卷：18
• 期：16
• 页码：4124-4127
• 全文大小：299K
• 年卷期：0
• ISSN：1523-7052

文摘

The ability to affect asymmetric reduction of heterocyclic β-aminoacrylates 1 (n = 1–3) has been assessed with pyrrolidine and piperidone variants generating the corresponding N-heterocyclic β²-amino acids 3b and 5b with high enantioselectivity (≥97% ee) using a Rh/WALPHOS catalyst combination. The use of the carboxylic acid substrate was essential; the corresponding esters do undergo reduction but led to racemic products. The seven-ring azepanone variant (as the carboxylic acid 9b) underwent reduction, but only a minimal level of asymmetric induction was observed.