Cycloamination strategies for renewable N-heterocycles

Cycloamination strategies for renewable N-heterocycles

Recently, Dr. H Li and Prof. Zhen Fang, collaborated with Prof. RL Smith Jr. (Tohoku University, Japan), published a review (Spotlight) paper in Green Chemistry about the production of renewable N-heterocycles.

Biomass resources have infinite possibilities for introducing nitrogen, sulfur, or phosphorus heteroatoms into their structures by virtue of controllable carbon-heteroatom bond formation. In this review, cycloamination approaches for thermal (catalyst-free) and catalytic transformation of biomass feedstocks into N-heterocyclic molecules including mechanistic pathways are analyzed. Bottom-up (small molecule substrates) and top-down (large molecule substrates) are considered. Sustainable routes for synthesis of five-membered (pyrroles, pyrrolidones, pyrazoles, imidazoles), six-membered (pyridines, pyrazines), fused (indoles, benzimidazoles), and other relevant azaheterocycles are critically assessed. Production of biomass-derived six-, seven-, and eight-membered as well as fused N-heterocyclic compounds with present approaches have relatively low selectivities. Attention to methods for forming analogous sulfur or phosphorus heteroatom compounds from biomass resources using either bottom-up or top-down strategies appear to have been greatly overlooked. Synthetic auxiliaries (heating modes, nitrogen sources) that enhance reaction efficiency and tunability of N-heterocyclic ring size/type are considered and plausible reaction mechanisms for pivotal pathways are developed.

Efficient amination strategies for synthesis of N-heterocycles from functional molecules (bottom-up) or from biomass (top-down) via sustainable C-N/C-X bond chemistry (从功能分子(自下而上)或从生物质(自上而下)通过可持续碳- n /C-X键化学合成n杂环的高效胺化策略)

Related results were accepted in Green Chemistry:

H Li*, HX Guo, Zhen Fang*, TM Aida, RL Smith Jr*, Cycloamination Strategies for Renewable N-heterocycles, Green Chemistry, https://doi.org/10.1039/C9GC03655E , 22, 582-611, 2020 (Spotlight Paper, Review).

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李虎博士在国际学术期刊Green Chemistry发表学术论文

可再生氮杂环的环胺化策略

最近,国际学术期刊Green Chemistry(影响因子9.4, Q1,第一署名单位为南京农业大学,第一作者为李虎博士,通讯作者为李虎博士,方真教授和日本东北大学RL Smith Jr教授)以Spotlight paper形式,发表了生物质生产可再生氮杂环化合物的综述。

生物质资源通过可控的碳-杂原子成键将氮、硫、磷等杂原子引入其结构中具有无限的可能性。本文综述了近年来生物质原料热(无催化)和催化转化为n -杂环分子的环胺化方法及其机理。考虑自底向上(小分子底物)和自顶向下(大分子底物)。五元(吡咯、吡咯烷酮、吡唑、咪唑)、六元(吡啶)的合成路线。用现有方法生产生物衍生的六元、七元、八元以及融合的n杂环化合物的选择性较低。利用自底向上或自顶向下的战略从生物量资源中形成类似硫或磷杂原子化合物的方法似乎受到了极大的忽视。考虑了提高反应效率和n杂环尺寸/类型可调性的合成助剂(加热方式、氮源),并建立了关键途径的合理反应机制。

详情可见:

H Li*, HX Guo, Zhen Fang*, TM Aida, RL Smith Jr*, Cycloamination Strategies for Renewable N-heterocycles, Green Chemistry (IF 9.4), https://doi.org/10.1039/C9GC03655E 22, 582-611, 2020 (Spotlight Paper, Review).