Acidic Magnetic Biocarbon-Enabled Upgrading of Biomass-Based Hexanedione into Pyrroles  

作　　者：Zhimei Li Kuan Tian Keping Wang Zhengyi Li Haoli Qin Hu Li 

机构地区：[1]School of Chemistry and Materials Science,Guizhou Normal University,Guiyang,550001,China [2]National Key Laboratory of Green Pesticide,Key Laboratory of Green Pesticide and Agricultural Bioengineering,Ministry of Education,State-Local Joint Laboratory for Comprehensive Utilization of Biomass,Center for R&D of Fine Chemicals of Guizhou University,Guiyang,550025,China

出　　处：《Journal of Renewable Materials》2023年第11期3847-3865,共19页可再生材料杂志（英文）

基　　金：funded by the Guizhou Provincial S&T Project(ZK[2022]011);Guizhou Natural Science Foundation(20201Y182);College Students’Innovation and Entrepreneurship Training Program(S202110657036).

摘　　要：Sustainable acquisition of bioactive compounds from biomass-based platform molecules is a green alternative for existing CO_(2)-emitting fossil-fuel technologies.Herein,a core–shell magnetic biocarbon catalyst functionalized with sulfonic acid(Fe3O4@SiO_(2)@chitosan-SO_(3)H,MBC-SO_(3)H)was prepared to be efficient for the synthesis of various N-substituted pyrroles(up to 99% yield)from bio-based hexanedione and amines under mild conditions.The abundance of Bronsted acid sites in the MBC-SO_(3)H ensured smooth condensation of 2,5-hexanedione with a variety of amines to produce N-substituted pyrroles.The reaction was illustrated to follow the conventional Pall-Knorr coupling pathway,which includes three cascade reaction steps:amination,loop closure and dehydration.The prepared MBC-SO_(3)H catalyst could effectively activate 2,5-hexanedione,thus weakening the dependence of the overall conversion process on the amine nucleophilicity.The influence of different factors(e.g.,reaction temperature,time,amount of catalyst,molar ratio of substrates,and solvent type)on the reaction activity and selectivity were investigated comprehensively.Moreover,the MBC-SO_(3)H possessed excellent thermochemical stability,reusability,and easy separation due to the presence of magnetic core-shell structures.Notably,there was no activity attenuation after 5 consecutive catalytic experiments.This work demonstrates a wide range of potential applications of developing functionalized core-shell magnetic materials to construct bioactive backbones from biomass-based platform molecules.

关 键 词：Magnetic materials biomass conversion heterogeneous catalysis sustainable chemistry 

分 类 号：O62[理学—有机化学]