Electrochemical dicarboxylation of conjugated fatty acids as an efficient valorization of carbon dioxide
作者:Roman Matthessen、Jan Fransaer、Koen Binnemans、Dirk E. De Vos
DOI:10.1039/c3ra00129f
日期:——
Carbon dioxide was electrochemically incorporated in internal conjugated dienes and the process was optimized to achieve satisfactory yields (>70%) even for less reactive substrates. Reactions were performed galvanostatically in an undivided cell at room temperature with a magnesium or aluminium sacrificial anode. Using an optimized electrosynthetic method for the dicarboxylation of 1,3-cyclohexadiene (optimal electrode material, CO2 pressure, amount of charge), the effect of molecular configuration and alkyl substitution on the reactivity of conjugated double bonds towards carboxylation was studied. Use of a bubble reactor at atmospheric pressure instead of a higher pressure reactor, and lowering of the current density made it possible to effectively perform the double carboxylation of internal conjugated double bonds in open chains. Conjugated linoleic acid methyl esters were used in this reaction for the first time and by searching for the optimal reaction conditions (solvent, supporting electrolyte, reactant concentration, amount of charge, current density) yields approaching 80% of the corresponding fatty triacid product could be obtained, at current efficiencies over 50%.
二氧化碳通过电化学方法与内部共轭二烯烃结合,并对该过程进行了优化,即使是反应性较低的基质也能获得令人满意的产率(大于 70%)。反应在室温下的不分流电池中以牺牲阳极镁或铝进行静电反应。使用优化的电合成方法(最佳电极材料、二氧化碳压力、电荷量)对 1,3-环己二烯进行二羧化,研究了分子构型和烷基取代对共轭双键羧化反应活性的影响。在常压下使用气泡反应器而不是高压反应器,并降低电流密度,可以有效地对开放链中的内部共轭双键进行双羧化反应。共轭亚油酸甲酯首次用于该反应,通过寻找最佳反应条件(溶剂、支持电解质、反应物浓度、电荷量、电流密度),可获得接近 80% 的相应脂肪三酸产物,电流效率超过 50%。