Deuterated organic compounds have gained significant attention due to their diverse applications, including reaction mechanism studies, probes for metabolism and pharmacokinetics, and raw materials for labeled compounds and polymers. Conventional reductive deuteration methods are limited by the high cost of deuterium sources (e.g., D₂ gas) and challenges in product separation and D₂O recycling. Electrochemical deuteration using D₂O is promising, but existing methods still suffer from low Faradaic efficiency (FE) and high separation costs. Herein, we report a deuterium ion diffusion-based all-solid electrolyser, featuring a RuO₂ anode for D + generation from pure D 2 O and a Pd/nitrogen-doped carbon-based liquid diffusion cathode (Pd δ+ /NC LDC) with tunable electron deficiencies Pd δ+ /NC to enhance selective deuteration. This system achieves over 99% selectivity for deuterated benzyl alcohol with a FE of 72%, and demonstrates broad applicability for the deuteration of aldehydes, ketones, imines, and alkenes with high FE and selectivity. Moreover, the Pd δ+ /NC-based electrolyser can achieve ten-gram-scale production of deuterated benzyl alcohol over 500 hours, showcasing its potential for high-throughput, solvent-free deuteration reactions in practical applications.
Hong-Yan Wang,Yu-Li Xie,Xin Shi,Hong-Ling Shi,Jian-He Xu,Cun-Duo Tang,Lun-Guang Yao,Yun-Chao Kan
Halogenated mandelate and its derivatives are important scaffolds in chemical industry. However, the natural D -mandelate dehydrogenase (DMDH) showed relatively low catalytic activity toward D -o-chloromandelic acid, which largely limits the efficiency of dehydrogenation processes. To improve catalytic activity of Lactobacillus brevis D -mandelate dehydrogenase ( Lb DMDH) toward halogenated substrate, a D -mandelate dehydrogenase mutant Lb DMDH N253S with higher catalytic activity toward D -o-chloromandelic acid was successfully obtained by directed evolution, which was about 29 times of Lb DMDH. In addition, the temperature optimum of Lb DMDH N253S is 50 °C, and closer to the optimal growth temperature for Escherichia coli , indicating that it may be more advantageous in whole cell catalysis using living cells as catalysts. Meanwhile, the K cat value toward D -o-chloromandelic acid of Lb DMDH N253S is 2.08 s −1 , which is significantly higher than the one (0.09 s −1 ) of Lb DMDH, indicating that Lb DMDH N253S displayed higher catalytic efficiency toward D -o-chloromandelic acid. Then, we preliminarily explained the molecular basis for its catalytic performance by in silico design methods. All of these results established a solid foundation for molecular modification of DMDHs and the other industrial enzymes.