Direct Access to Trifluoromethyl-Substituted Carbamates from Carbon Dioxide via Copper-Catalyzed Cascade Cyclization of Enynes
作者单位：Key Laboratory of Functional Molecular Engineering of Guangdong Province School of Chemistry and Chemical EngineeringSouth China University of Technology
会议名称：《中国化学会·第一届全国二氧化碳资源化利用学术会议》
会议日期：2019年
学科分类：081704[工学-应用化学] 07[理学] 08[工学] 0817[工学-化学工程与技术] 070303[理学-有机化学] 0703[理学-化学]
关 键 词：trifluoromethylated carbamates copper-catalyzed carbon dioxide enynes
摘 要：Organic carbamates constitute an important class of bioactive compounds, which widely exist in many natural products, pharmaceuticals, and agrochemicals. They could also serve as versatile building blocks in organic synthesis. Recently, CO has emerged as an attractive alternative to phosgene for the synthesis of carbamates because of its advantages such as nontoxicity, natural abundance, and renewability. Many multicomponent reactions involving the use of halohydrocarbons, alcohols, unsaturated hydrocarbons, or other compounds as the coupling partners have been reported for the assembly of carbamates. In recent years, our group has also developed several novel multicomponent reactions for the synthesis of organic carbamates. On the other hand, it is commonly accepted that the incorporation of fluorine or fluorine-containing functional groups into organic compounds could substantially alter their physical and chemical properties, which may be beneficial for improving their biological activities. Herein, we wish to report a copper-catalyzed radical cascade cyclization of enynes with Togni’s reagent in the presence of CO and amines, providing a direct and efficient protocol for the synthesis of a diverse range of trifluoromethylated carbamates, which are difficult to access using existing methods(Figure 1).