Asymmetric Intramolecular Oxa-Michael Reactions of Cyclohexadienones Catalyzed by a Primary Amine Salt
作者:Wenbin Wu、Xin Li、Huicai Huang、Xiaoqian Yuan、Junzhu Lu、Kailong Zhu、Jinxing Ye
DOI:10.1002/anie.201206977
日期:2013.2.4
Michael brings the rings: An asymmetricintramolecular oxa‐Michael reaction involving iminium activation has been developed. This reaction provides enantioenriched 1,4‐dioxane derivatives with up to 99 % yield and 98 % ee. The method allows for concise and stereoselective access to stereodiverse, complex tetracyclic compounds containing a bicyclo[2.2.2]octan‐2‐one backbone with multiple chiral centers
condensation–dimerization reaction of l-proline with 2,5-cyclohexadienones including p-quinone monoacetals, p-quinol ethers, and p-quinols is reported to provide a concise and rapid synthesis of octahydro-dipyrroloquinoline compounds. The reaction features the use of cost-effective and readily available starting materials, high efficiency, metal-free and green reaction conditions. The reaction is applied to the
Desymmetrization of Cyclohexadienones through Phase-Transfer-Catalyzed Stereoselective Intramolecular Aza-Michael Addition with Chiral Sulfinamide Nucleophiles
This paper reports the desymmetrization of cyclohexadienones through stereoselective intramolecularaza-Michael addition with a tethered chiral sulfinamide nucleophile. The reaction was facilitated by phase-transfer catalysis and produced various nitrogen-containing bicyclic compounds with a yield of up to 93% and a diastereomeric ratio of up to >20:1.
The iron(III) chloride‐catalyzed Friedel–Crafts arylation of 4‐aryl‐4‐methoxy‐2,5‐cyclohexadienones, which were easily prepared by the phenyliodine(III) diacetate (PIDA)‐mediated oxidation of 4‐arylphenols in methanol, proceeded site‐selectively to form meta‐terphenyl (2,4‐diarylphenol) derivatives in good yields. The subsequent PIDA‐mediated oxidation and iron(III) chloride‐catalyzed Friedel–Crafts
cyclohexadienones and primary amines has been developed. The aza-Michael addition of the in situ formed enamine, generated through the condensation of carboxymethyl unit of the substrates with an external amine, to cyclohexadienone moiety followed by rearomatization reaction to provide such indoles. Anilines, aliphatic amines, α-chiral aliphatic amines, or even ammonia were used as amine counterpart. Some of
已经开发了由羧甲基环己二酮和伯胺有效地无催化剂合成6-羟基吲哚的方法。通过底物的羧甲基单元与外部胺的缩合产生的原位形成的烯胺的氮杂-迈克尔加成至环己二烯酮部分,然后进行重新芳构化反应以提供这种吲哚。苯胺,脂肪族胺,α-手性脂肪族胺,甚至氨水都用作胺的对应物。使用Re 2 O 7催化剂,一些环己二酮生成6-氨基吲哚而不是6-羟基吲哚。进行了各种方法学后转换,以探索合成的羟基吲哚的合成效用。