Nitroalkenes as Latent 1,2-Biselectrophiles - A Multicatalytic Approach for the Synthesis of 1,4-Diketones and Their Application in a Four-Step One-Pot Reaction to Polysubstituted Pyrroles
Nitroalkenes as Latent 1,2-Biselectrophiles - A Multicatalytic Approach for the Synthesis of 1,4-Diketones and Their Application in a Four-Step One-Pot Reaction to Polysubstituted Pyrroles
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DOI：
10.1021/acs.joc.7b00830
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发表时间：
2017-08-04
影响因子：
3.6
通讯作者：
Zeitler, Kirsten
中科院分区：
文献类型：
--
作者：
Fuchs, Patrick J. W.;Zeitler, Kirsten
NHC 催化的硝基-Stetter/消除/Stetter 反应序列采用硝基烯烃作为潜在的 1,2-双阳离子合成子，提供了从市售醛前体获得高度有用的对称和不对称 2-芳基取代的 1,4-二酮结构单元的新途径。对于活性较低的（脂肪族）醛，通过 NHC 和氢键催化的合并开发了一种协同催化策略。为了进一步展示我们方法的多功能性，我们使用多种前所未有的1,4-二酮来有效合成多取代吡咯，包括那些具有杂芳基取代基的吡咯，在温和而稳健的条件下，在多催化无金属、四步一锅级联反应中，以良好至优异的产率合成多取代吡咯。
An NHC-catalyzed nitro-Stetter/elimination/Stetter reaction sequence employs nitroalkenes as latent 1,2-dication synthons providing a novel access to highly useful symmetrical and unsymmetrical 2-aryl substituted 1,4-diketone building blocks from commercially available aldehyde precursors. For less activated (aliphatic) aldehydes, a cooperative catalytic strategy has been developed via the merger of NHC and H-bonding catalysis. To further showcase the versatility of our approach, a great variety of these unprecedented 1,4-diketones are used to efficiently synthesize polysubstituted pyrroles-including those with hetaryl substituents in good to excellent yields in a multicatalytic metal-free, four-step one-pot cascade reaction under mild, yet robust, conditions.