Wang Ruopeng, Nakao Kaiki, Manaka Yuichi, Motokura Ken
Department of Chemistry and Life Sciences, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama, 240-8501, Japan.
Department of Chemical Science and Engineering, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, 226-8502, Japan.
Commun Chem. 2022 Nov 16;5(1):150. doi: 10.1038/s42004-022-00767-4.
Metallic silicon could be an inexpensive, alternative reducing agent for CO functionalization compared to conventionally used hydrogen or hydrosilanes. Here, metallic silicon recovered from solar panel production is used as a reducing agent for formamide synthesis. Various amines are converted to their corresponding amides with CO and HO via an Si-H intermediate species in the presence of a catalytic amount of tetrabutylammonium fluoride. The reaction system exhibits a wide substrate scope for formamide synthesis. Spectroscopic analysis, including in situ Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), N adsorption/desorption analyses, and isotopic experiments reveal that the fluoride catalyst effectively oxidizes Si atoms on both surface and interior of the powdered silicon particles. The solid recovered after catalysis contained mesopores with a high surface area. This unique behavior of the fluoride catalyst in the presence of metallic silicon may be extendable to other reductive reactions, including those with complex substrates. Therefore, this study presents a potential strategy for the efficient utilization of abundant resources.
与传统使用的氢气或硅烷相比，金属硅可能是一种用于CO官能化的廉价替代还原剂。在这里，从太阳能电池板生产中回收的金属硅被用作甲酰胺合成的还原剂。在催化量的四丁基氟化铵存在下，各种胺通过Si-H中间物种与CO和HO反应转化为相应的酰胺。该反应体系在甲酰胺合成方面具有广泛的底物范围。包括原位傅里叶变换红外光谱（FTIR）、X射线光电子能谱（XPS）、X射线衍射（XRD）、N吸附/脱附分析和同位素实验在内的光谱分析表明，氟化物催化剂能有效氧化粉末状硅颗粒表面和内部的Si原子。催化后回收的固体含有具有高表面积的中孔。氟化物催化剂在金属硅存在下的这种独特行为可能适用于其他还原反应，包括那些涉及复杂底物的反应。因此，本研究提出了一种有效利用丰富资源的潜在策略。
