Department of Electronic Chemistry, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, 2268502, Japan.
Org Biomol Chem. 2011 Jun 7;9(11):4256-65. doi: 10.1039/c1ob05174a. Epub 2011 Apr 11.
Product selectivity control based on a liquid-liquid parallel laminar flow has been successfully demonstrated by using a microreactor. Our electrochemical microreactor system enables regioselective cross-coupling reaction of aldehyde with allylic chloride via chemoselective cathodic reduction of substrate by the combined use of suitable flow mode and corresponding cathode material. The formation of liquid-liquid parallel laminar flow in the microreactor was supported by the estimation of benzaldehyde diffusion coefficient and computational fluid dynamics simulation. The diffusion coefficient for benzaldehyde in Bu(4)NClO(4)-HMPA medium was determined to be 1.32 × 10(-7) cm(2) s(-1) by electrochemical measurements, and the flow simulation using this value revealed the formation of clear concentration gradient of benzaldehyde in the microreactor channel over a specific channel length. In addition, the necessity of the liquid-liquid parallel laminar flow was confirmed by flow mode experiments.
基于液-液平行层流的产物选择性控制已成功通过微反应器得以实现。我们的电化学微反应器系统通过使用合适的流动模式和相应的阴极材料，实现了底物的化学选择性阴极还原，从而使醛与烯丙基氯的区域选择性交叉偶联反应成为可能。通过对苯甲醛扩散系数的估算和计算流体动力学模拟，支持了微反应器中液-液平行层流的形成。通过电化学测量确定苯甲醛在 Bu(4)NClO(4)-HMPA 介质中的扩散系数为 1.32×10(-7)cm(2)s(-1)，并使用该值进行的流动模拟显示，在特定的通道长度上，微反应器通道中苯甲醛形成了清晰的浓度梯度。此外，通过流动模式实验证实了液-液平行层流的必要性。
