Konik Yulia A, Kudrjashova Marina, Konrad Nele, Kaabel Sandra, Järving Ivar, Lopp Margus, Kananovich Dzmitry G
Department of Organic Chemistry, Belarusian State University, Leningradskaya 14, 220050, Minsk, Belarus.
Org Biomol Chem. 2017 May 31;15(21):4635-4643. doi: 10.1039/c7ob00680b.
Tertiary cyclopropanols easily available from carboxylic esters have been used in the synthesis of distally fluorinated ketones. Cyclopropane ring cleavage reactions in methanol with aqueous tert-butyl hydroperoxide in the presence of a copper(ii) acetate catalyst and sodium triflinate (Langlois reagent) afford β-trifluoromethyl ketones in 16-74% isolated yields. Sodium triflinate serves as a precursor of reactive trifluoromethyl copper species, enabling ring-opening trifluoromethylation, as evidenced by mechanistic studies. We also demonstrate here that other sulfinate salts, such as sodium 1,1-difluoroethanesulfinate, sodium 2-(4-bromophenyl)-1,1-difluoroethanesulfinate and sodium 1-(trifluoromethyl)cyclopropanesulfinate, can be used as fluoroalkylation reagents, resulting in the corresponding fluorinated ketones.
可从羧酸酯轻松获得的叔环丙醇已用于远端氟化酮的合成。在乙酸铜（II）催化剂和三氟甲磺酸钠（朗格卢瓦试剂）存在下，叔丁基过氧化氢水溶液在甲醇中进行的环丙烷环裂解反应，可得到分离产率为16-74%的β-三氟甲基酮。机理研究表明，三氟甲磺酸钠作为活性三氟甲基铜物种的前体，可实现开环三氟甲基化。我们在此还证明，其他亚磺酸盐，如1,1-二氟乙烷亚磺酸钠、2-（4-溴苯基）-1,1-二氟乙烷亚磺酸钠和1-（三氟甲基）环丙烷亚磺酸钠，可用作氟烷基化试剂，从而得到相应的氟化酮。
