Synthesis of 2,6-Disubstituted Piperazines by a Diastereoselective Palladium-Catalyzed Hydroamination Reaction

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• 作者：Brian M. Cochran ; Forrest E. Michael
• 刊名：Organic Letters
• 出版年：2008
• 出版时间：January 17, 2008
• 年：2008
• 卷：10
• 期：2
• 页码：329 - 332
• 全文大小：84K
• 年卷期：v.10,no.2(January 17, 2008)
• ISSN：1523-7052

文摘

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A highly diastereoselective intramolecular hydroamination is the key step in a modular synthesis of 2,6-disubstituted piperazines. The requisitehydroamination substrates were prepared in excellent yields by nucleophilic displacement of cyclic sulfamidates derived from amino acids.A variety of alkyl and aryl substituents at the 2-position were tolerated. The stereochemistry of the piperazines was determined to be transby X-ray crystallography, which also showed the preferred conformation of the 2,6-disubstituted piperazine to be a twist-boat due to A_1,3strain.