Liang Fengying, Eda Kazuo, Okazoe Takashi, Wada Akihiro, Mori Nobuaki, Konishi Katsuhiko, Tsuda Akihiko
Department of Chemistry, Graduate School of Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan.
Materials Integration Laboratories, AGC Inc., Suehiro 1-1 Tsurumi-ku, Yokohama City, Kanagawa 230-0045, Japan.
J Org Chem. 2021 May 7;86(9):6504-6517. doi: 10.1021/acs.joc.1c00334. Epub 2021 Apr 12.
The Vilsmeier reagent (VR), first reported a century ago, is a versatile reagent in a variety of organic reactions. It is used extensively in formylation reactions. However, the synthesis of VR generally requires highly toxic and corrosive reagents such as POCl, SOCl, or COCl. In this study, we found that VR is readily obtained from a CHCl solution containing ,-dimethylformamide or ,-dimethylacetamide upon photo-irradiation under O bubbling. The corresponding Vilsmeier reagents were obtained in high yields with the generation of gaseous HCl and CO as byproducts to allow their isolations as crystalline solid products amenable to analysis by X-ray crystallography. With the advantage of using CHCl, which bifunctionally serves as a reactant and a solvent, this photo-on-demand VR synthesis is available for one-pot syntheses of aldehydes, acid chlorides, formates, ketones, esters, and amides.
维尔施迈尔试剂（VR）于一个世纪前首次被报道，是一种在各种有机反应中用途广泛的试剂。它在甲酰化反应中被广泛使用。然而，VR的合成通常需要剧毒且腐蚀性强的试剂，如POCl、SOCl或COCl。在本研究中，我们发现，在通入O₂的情况下对含有N，N-二甲基甲酰胺或N，N-二甲基乙酰胺的CHCl₃溶液进行光照射时，很容易得到VR。相应的维尔施迈尔试剂以高产率获得，同时生成气态HCl和CO作为副产物，从而能够将它们分离为适合通过X射线晶体学分析的结晶固体产物。由于使用了兼具反应物和溶剂双重功能的CHCl₃，这种按需光合成VR的方法可用于醛、酰氯、甲酸酯、酮、酯和酰胺的一锅法合成。
