Sytniczuk Adrian, Dąbrowski Michał, Banach Łukasz, Urban Mateusz, Czarnocka-Śniadała Sylwia, Milewski Mariusz, Kajetanowicz Anna, Grela Karol
Faculty of Chemistry, Biological and Chemical Research Centre , University of Warsaw , Żwirki i Wigury 101 , 02-089 Warsaw , Poland.
J Am Chem Soc. 2018 Jul 18;140(28):8895-8901. doi: 10.1021/jacs.8b04820. Epub 2018 Jul 6.
Macrocyclic lactones, ketones, and ethers can be obtained in the High-Concentration Ring-Closing Metathesis (HC-RCM) reaction in high yield and selectivity at concentrations 40 to 380 times higher than those typically used by organic chemists for similar macrocyclizations. The new method consists of using tailored ruthenium catalysts together with applying vacuum to distill off the macrocyclic product as it is formed by the metathetical backbiting of oligomers. Unlike classical RCM, no large quantities of organic solvents are used, but rather inexpensive nonvolatile diluents, such as natural or synthetic paraffin oils. Moreover, use of a protecting atmosphere or a glovebox is not needed, as the new catalysts are perfectly moisture and air stable. In addition, some other cyclic compounds previously reported as unobtainable by RCM in neat conditions, or in high dilutions even, can be formed with the help of the HC-RCM method.
大环内酯、酮和醚可通过高浓度关环复分解（HC-RCM）反应以高产率和选择性获得，其浓度比有机化学家通常用于类似大环化反应的浓度高40至380倍。新方法包括使用定制的钌催化剂，并在低聚物的复分解咬环反应形成大环产物时，通过抽真空将其蒸馏出来。与传统的RCM不同，该方法不使用大量有机溶剂，而是使用廉价的非挥发性稀释剂，如天然或合成石蜡油。此外，由于新催化剂对水分和空气具有完美的稳定性，因此无需使用保护气氛或手套箱。此外，借助HC-RCM方法，可以形成一些其他环状化合物，这些化合物以前在纯条件下或即使在高稀释度下也无法通过RCM获得。
