Siebert Max, Seibicke Max, Siegle Alexander F, Kräh Sabrina, Trapp Oliver
Department Chemie , Ludwig-Maximilians-Universität München , Butenandtstraße 5-13 , 81377 München , Germany.
J Am Chem Soc. 2019 Jan 9;141(1):334-341. doi: 10.1021/jacs.8b10233. Epub 2018 Dec 20.
Formaldehyde is an important precursor to numerous industrial processes and is produced in multimillion ton scale every year by catalytic oxidation of methanol in an energetically unfavorable and atom-inefficient industrial process. In this work, we present a highly selective one-step synthesis of a formaldehyde derivative starting from carbon dioxide and hydrogen gas utilizing a homogeneous ruthenium catalyst. Here, formaldehyde is obtained as dimethoxymethane, its dimethyl acetal, by selective reduction of carbon dioxide at moderate temperatures (90 °C) and partial pressures (90 bar H/20 bar CO) in the presence of methanol. Besides the desired product, only methyl formate is formed, which can be transformed to dimethoxymethane in a consecutive catalytic step. By comprehensive screening of the catalytic system, maximum turnover numbers of 786 for dimethoxymethane and 1290 for methyl formate were achieved with remarkable selectivities of over 90% for dimethoxymethane.
甲醛是众多工业过程的重要前体，每年通过甲醇催化氧化以数百万吨的规模生产，这是一个能量不利且原子利用效率低的工业过程。在这项工作中，我们展示了一种使用均相钌催化剂从二氧化碳和氢气出发，一步法高选择性合成甲醛衍生物的方法。在此过程中，甲醛以二甲氧基甲烷（其二甲醇缩醛）的形式通过在甲醇存在下于中等温度（90℃）和分压（90巴氢气/20巴二氧化碳）下选择性还原二氧化碳而获得。除了所需产物外，仅生成甲酸甲酯，其可在连续催化步骤中转化为二甲氧基甲烷。通过对催化体系的全面筛选，二甲氧基甲烷的最大周转数达到786，甲酸甲酯的最大周转数达到1290，二甲氧基甲烷的选择性超过90%，十分显著。
