Gold(I)-Catalyzed Cyclization-3-Aza-Cope-Mannich Cascade and Its Application to the Synthesis of Cephalotaxine
Gold(I)-Catalyzed Cyclization-3-Aza-Cope-Mannich Cascade and Its Application to the Synthesis of Cephalotaxine
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DOI：
10.1021/acs.orglett.1c01323
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发表时间：
2021-05-13
期刊：
影响因子：
5.2
通讯作者：
Mori, Yuji
中科院分区：
文献类型：
--
作者：
Sakai, Takeo;Okumura, Chise;Mori, Yuji
据报道，发现了一种新的金 (I) 催化级联反应，涉及乙烯基铵环化、3-氮杂-Cope 重排和曼尼希环化。使用 1-5 mol% 的 AuCl(PPh3)/Ag[C-5(CN)(5)] 助催化剂体系，由简单的环状叔胺制备了多种稠合氮杂环。所开发的反应用于旨在合成头孢噻嗪的研究。由去甲海天宁经五步操作得到去甲基头孢紫杉酮，总产率为39.1%，并分两步转化为(-)-头孢紫杉酮。
The discovery of a new gold(I)-catalyzed cascade reaction involving cyclization onto a vinylammonium, 3-aza-Cope rearrangement, and Mannich cyclization is reported. A variety of fused nitrogen heterocycles were prepared from simple cyclic tertiary amines using 1-5 mol % of a AuCl(PPh3)/Ag[C-5(CN)(5)] cocatalyst system. The developed reaction was used in a study aimed at synthesizing cephalotaxine. A five-step operation from norhydrastinine provided demethylcephalotaxinone in 39.1% overall yield, which was transformed to (-)-cephalotaxine in two steps.