气相色谱法辅助分析环状1,3-二羰基化合物的去对称对映选择性还原反应机理  

Study on Reaction Mechanism of Desymmetric Enantioselective Reduction of Cyclic 1,3-Diketones Aided by Gas Chromatography

作　　者：秦绪隆 韩福社[1,2] QIN Xu-Long;HAN Fu-She(Green Chemistry and Process Laboratory,Changchun Institute of Applied Chemistry,Chinese Academy of Sciences,Changchun 130022,China;University of Science and Technology of China,Hefei 230026,China)

机构地区：[1]中国科学院长春应用化学研究所绿色化学与过程实验室,长春130022 [2]中国科学技术大学,合肥230026

出　　处：《分析化学》2022年第2期290-299,共10页Chinese Journal of Analytical Chemistry

基　　金：国家自然科学基金项目(No.22071235)资助。

摘　　要：建立了一种利用气相色谱(GC)检测1,3-环戊二酮化合物去对称对映选择性还原反应转化率和产物含量的方法,作为一种重要辅助手段,用于磷中心手性膦酰胺催化环状1,3-二酮类化合物的去对称对映选择性还原反应机理的研究。样品经DB-WAX色谱柱(30 m×0.25 mm,0.25μm)分离,以标准化合物比对的方法,采用GC进行定性及定量分析,可简便、快速、准确测定在不同反应时间剩余原料和生成的不同产物的量。采用本方法对无添加剂和催化剂、只加入添加剂、只加入催化剂以及同时加入添加剂和催化剂4种情况下的反应进程进行了检测。结果表明,相比其它3种反应体系,同时加入添加剂N,N-二异丙基乙胺(DIPEA)和催化剂的反应体系的原料转化速度快,在5 min内反应转化率达到80%以上,单还原目标产物的含量接近70%。对照实验结果表明,加入DIPEA可大幅提高产物的对映选择性。本研究结果有助于深入理解相关反应的机理,即胺类添加剂的加入可促进手性活性催化物种的生成。A gas chromatography(GC)method was established for determination of conversion rate and product content in the desymmetric enantioselective reduction of 1,3-cyclopentadione compounds.This method could be used as a useful supplementary method to investigate the mechanism of desymmetric enantioselective reduction of cyclic 1,3-diketones catalyzed by chiral phosphonamides.The samples were separated on a DB-WAX column(30 m×0.25 mm,0.25μm)and analyzed qualitatively and quantitatively by gas chromatography using a standard compound comparison method.The method could be used for convenient,rapid and accurate determination of content of the remaining starting materials and different products generated at different reaction time.By using the established detection method,the reaction course under four different reaction conditions(without additive and catalyst,with additive only,with catalyst only and with both additive and catalyst)were monitored in detail.The results showed that the reaction with the concomitant presence of N,N-diisopropylethylamine(DIPEA)and catalyst not only proceeded much faster but also provided higher yields compared with other three reaction systems.Namely,the conversion rate was up to 80%within 5 min,and the content of target product was close to 70%.In addition,control experiments showed that the addition of DIPEA could also greatly improve the enantioselectivity of the product.Consequently,a combination of these results with our previous mechanistic study by using NMR method provided a further understanding of the mechanism of the related reactions,namely,the addition of amine additives could promote the formation of chiral catalytically active species.

关 键 词：环状1 3-环戊二酮 去对称还原 气相色谱 添加剂 转化率 

分 类 号：O657.71[理学—分析化学] O621.25[理学—化学]