环醚直接双羰基化合成α,ω-二元羧酸  

Direct synthesis of α,ω‐dicarboxylic acids via dicarbonylation of cyclic ethers

作　　者：马长坡 赖楹 赵天歌 张小炫 刘海超[2] 杨维冉 Changpo Ma;Ying Lai;Tiange Zhao;Xiaoxuan Zhang;Haichao Liu;Weiran Yang(School of Chemistry and Chemical Engineering,Nanchang University,Nanchang 330031,Jiangxi,China;Beijing National Laboratory for Molecular Sciences,College of Chemistry and Molecular Engineering,Peking University,Beijing 100871,China)

机构地区：[1]南昌大学化学化工学院,江西南昌330031 [2]北京大学化学与分子工程学院,北京分子科学国家研究中心,北京100871

出　　处：《Chinese Journal of Catalysis》2024年第1期122-129,共8页催化学报（英文）

基　　金：国家自然科学基金(22169011).

摘　　要：二元羧酸是制备聚酰胺、聚酯和聚氨酯的重要中间体,其传统合成途径具有一定的局限性.以己二酸为例,其主要工业生产工艺是利用硝酸氧化KA油,该方法存在KA油产量低和产生大量温室气体N2O等问题.因此,探索工艺绿色、原子有效和采用可再生原料的二元羧酸制备方法具有重要意义.环醚和多元醇很容易从生物质原料中得到,以它们为原料,通过双羰基化直接制备二元羧酸,是一种非常有潜力的反应途径.但目前大多数文献报道由环醚或多元醇通过羰基化反应生成的产物主要是C+1单羧酸.本课题组一直致力于碘催化生物质衍生的多元醇的加氢脱氧,研究发现,在特定的反应条件下,多元醇可以选择性地形成多碘取代化合物的中间体.受此启发,本文报道了一种由环醚或多元醇形成二碘代物中间体,然后直接通过双羰基化反应生成对应的C+2二羧酸的新策略.由于己二酸是最重要的二元羧酸之一,且四氢呋喃(THF)可以从丰富的生物质衍生的糠醛中获得,本文重点研究了通过双羰基化反应直接利用THF合成己二酸.在优化的反应条件下,以铑盐为催化剂,碘为促进剂,乙酸和水为混合溶剂,在170℃,CO和H_(2)条件下,THF可以84%的产率转化为己二酸.循环实验结果表明,该催化体系在5次循环后仍能够稳定运行.该催化体系不仅适用于各种环醚,也适用于不同的伯二醇合成对应的C+2α,ω-二元羧酸.通过对反应中间体进行检测以及控制实验研究发现,选择性生成1,4-二碘丁烷中间体是进一步双羰基化制备己二酸的关键,而生成烯烃中间体和单碘代物中间体是形成副产物戊酸的主要原因.在实验结果和文献研究基础上,提出了THF转化为己二酸的反应机理.在反应中,活性铑常以Rh(I)的形式存在,并且从质谱中观察到了[Rh(CO)_(2)I_(2)]−阴离子,它可以在羰基化条件下由不同的铑前体(例如RhCl_(3))经过CO和�α,ω-Dicarboxylic acids are important intermediates for the preparation of polyamides,polyesters and polyurethanes.However,their production pathways are limited and usually suffer from low efficiency and environmental problems.Here,we report an innovative approach to synthesize C+2 dicarboxylic acids directly from cyclic ethers by dicarbonylation.Different from the general findings that C+1 monocarboxylic acids are produced by carbonylation of cyclic ethers involving alkene intermediates,in this work,by manipulating the reaction system with RhCl_(3) and iodine in acetic acid,diiodide-substituted intermediates were selectively formed and subsequently converted to dicarboxylic acids in the presence of H_(2) and CO.As high as 84% yield of adipic acid was obtained directly from tetrahydrofuran.This catalytic system is applicable not only to a wide variety of cyclic ethers but also to different primary diols to synthesize C_(2)-elongatedα,ω-dicarboxylic acids.This work provides a novel dicarbonylation strategy for the efficient synthesis of adipic acid,glutaric acid and other importantα,ω-dicarboxylic acids(such as 1,7-heptanedioic acid and 1,8-octanedioic acid)that are still not easily synthesized by other methods.

关 键 词：α ω-二元羧酸 双羰基化 环醚 多元醇 己二酸 

分 类 号：TQ235[化学工程—有机化工]