Direct Catalytic Chemoselective α-Amination of Acylpyrazoles: A Concise Route to Unnatural α-Amino Acid Derivatives

Keisuke Tokumasu, Ryo Yazaki, Takashi Ohshima

研究成果: ジャーナルへの寄稿学術誌査読

82 被引用数 (Scopus)

抄録

A direct copper-catalyzed highly chemoselective α-amination is described. Acylpyrazole proved to be a highly efficient enolate precursor of a carboxylic acid oxidation state substrate, while preactivation by a stoichiometric amount of strong base has been used in catalytic α-aminations. The simultaneous activation of both coupling partners, enolization and metal nitrenoid formation, was crucial for obtaining the product, and wide functional group compatibility highlighted the mildness of the present catalysis. The bidentate coordination mode was amenable to highly chemoselective activation over ketone and much more acidic nitroalkyl functionality. Deuterium exchange experiments clearly demonstrated that exclusive enolization of acylpyrazole was achieved without the formation of a nitronate. The present catalysis was applied to late-stage α-amination, allowing for concise access to highly versatile α-amino acid derivatives. The product could be transformed into variety of useful building blocks.

本文言語英語
ページ(範囲)2664-2669
ページ数6
ジャーナルJournal of the American Chemical Society
138
8
DOI
出版ステータス出版済み - 3月 2 2016

!!!All Science Journal Classification (ASJC) codes

  • 触媒
  • 化学一般
  • 生化学
  • コロイド化学および表面化学

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