Alpha'-hydroxyenones as mechanistic probes and scope-expanding surrogates for alpha,beta-unsaturated aldehydes in N-heterocyclic carbene-catalyzed reactions.
Alpha'-hydroxyenones as mechanistic probes and scope-expanding surrogates for alpha,beta-unsaturated aldehydes in N-heterocyclic carbene-catalyzed reactions.
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DOI：
10.1021/ja902143w
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发表时间：
2009-06-24
影响因子：
15
通讯作者：
Bode JW
中科院分区：
文献类型：
--
作者：
Chiang PC;Rommel M;Bode JW
n -杂环碳烯催化的α、β-不饱和醛和各种亲电试剂的反应可以很容易地制备各种环化产物，包括三取代环戊烯、γ-内酰胺和双环β-内酰胺。然而，这些反应的底物范围受到制备起始α，β-不饱和醛的困难的限制。我们现在报道，α′-羟基烯酮可以在一个简单的步骤中由芳香和杂芳香醛制备，可以在环化反应中作为烯醛的有效替代品。该方案允许简便地制备和使用含氮杂环的底物。这些试剂也使我们证明，与其他类醛相比，在反应条件下，由烯醛和n杂环碳烯形成的Breslow中间体是不可逆的。
N-heterocyclic carbene catalyzed reactions of α,β-unsaturated aldehydes and a variety of electrophiles allow the facile preparation of a diverse array of annulation products including tri-substituted cyclopentenes, γ-lactams, and bicyclic β-lactams. The substrate scope of these reactions, however, is limited by the difficulties of preparing the startingα,β-unsaturated aldehydes. We now report that α′-hydroxyenones, which can be prepared in a single convenient step from aromatic and heteroaromatic aldehydes, can serve as efficient surrogates for enals in the annulation reactions. This protocol allows the facile preparation and use of substrates bearing nitrogen heterocycles. These reagents have also allowed us to demonstrate that, in contrast to other classes of aldehydes, the formation of the Breslow intermediate from enals and N-heterocyclic carbenes is irreversible under the reaction conditions.
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DOI：
10.1021/je60039a037
发表时间：
1968-01-01
期刊：
JOURNAL OF CHEMICAL AND ENGINEERING DATA
影响因子：
--
作者：
KING, GG;KARABINO.JV
通讯作者：
KARABINO.JV
影响因子：
15
作者：
Liu, Qin;Perreault, Stephane;Rovis, Tomislav
通讯作者：
Rovis, Tomislav
影响因子：
4.9
作者：
Li, Gong-Qiang;Dai, Li-Xin;You, Shu-Li
通讯作者：
You, Shu-Li
影响因子：
15
作者：
Chiang, Pei-Chen;Kaeobamrung, Juthanat;Bode, Jeffrey W.
通讯作者：
Bode, Jeffrey W.
影响因子：
16.6
作者：
Johnson, JS
通讯作者：
Johnson, JS