Synthesis of 2,5-disubstituted pyrroles via dehydrogenative condensation of secondary alcohols and 1,2-amino alcohols by supported platinum catalysts
Synthesis of 2,5-disubstituted pyrroles via dehydrogenative condensation of secondary alcohols and 1,2-amino alcohols by supported platinum catalysts
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DOI：
10.1039/c6qo00165c
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发表时间：
2016-06
影响因子：
5.4
通讯作者：
S. H. Siddiki;A. S. Touchy;Chandan Chaudhari;K. Kon;Takashi Toyao;K. Shimizu
中科院分区：
文献类型：
--
作者：
S. H. Siddiki;A. S. Touchy;Chandan Chaudhari;K. Kon;Takashi Toyao;K. Shimizu
利用非均相碳载铂催化剂（Pt/C），通过1，2-氨基醇和仲醇的无受体双杂环化反应，直接合成了2，5-二取代吡咯。优化后的方法在0.1mol%Pt/C和1.1equiv·mol-1的催化剂存在下，由2-氨基-1-丁醇和1-苯基乙醇反应生成目标产物2-乙基-5-苯基-1H-吡咯，产率为92%。关于KOTBU它已被揭示，Pt/C表现出上级的催化活性，在这项研究中测试的催化剂，包括其他过渡金属负载的碳和各种金属氧化物负载的Pt催化剂。此外，在本系统中获得的营业额（TON）被发现是高于那些在以前报道的催化系统中获得的。值得注意的是，Pt/C催化剂可以作为非均相催化剂循环使用而活性没有显著损失，并且显示出用于2，5-二取代吡咯形成过程的宽底物范围。
Direct synthesis of 2,5-disubstituted pyrroles has been achieved via acceptorless dehydrogenative heterocyclization of 1,2-aminoalcohols and secondary alcohols by utilizing a heterogeneous carbon-supported Pt catalyst (Pt/C). The optimized method gave 92% yield of 2-ethyl-5-phenyl-1H-pyrrole as a desired product from 2-amino-1-butanol and 1-phenylethanol in the presence of 0.1 mol% of Pt/C and 1.1 equiv. of KOtBu. It has been revealed that Pt/C demonstrates superior catalytic activity to a number of catalysts tested in this study including other transition metal-loaded carbon and various metal-oxide-supported Pt catalysts. In addition, the turnover number (TON) obtained in the present system was found to be higher than those obtained in previously-reported catalytic systems. It is significant that the Pt/C catalyst could be recycled as a heterogeneous catalyst without significant loss in the activity and showed a wide substrate scope for the 2,5-disubstituted pyrrole forming process.