A Novel Thermomorphic System for Electrocatalytic Diels‐Alder Reactions1. Issue 6 (15th April 2019) - Imada, Yasushi
Summary of main observation and conclusion: The discovery that lithium bis(trifluoromethane)sulfonamide (LiTFSI)/1‐nitropropane (PrNO2 ) solution functions as a less polar alternative to lithium perchlorate (LiClO4 )/nitromethane (MeNO2 ) solution has led to the development of a novel thermomorphic system for electrocatalytic Diels‐Alder reactions. Methyl cyclohexane (Me‐ c ‐Hex) can form a monophasic condition with LiTFSI/PrNO2 solution at room temperature, enabling the use of hydrophobic dienophiles. After the electrochemical reaction, a biphasic condition can be formed at –50°C, where the cycloadducts are selectively recovered from the upper Me‐ c ‐Hex phase and the remaining lower LiTFSI/PrNO2 solution can be reused. Abstract : Methyl cyclohexane can form a thermomorphic system with lithium bis(trifluoromethane)sulfonamide/1‐nitropropane solution, where biphasic and monophasic conditions were reversibly switched over a practical temperature range. The monophasic condition serves as a less polar electrolyte solution, enabling the use of hydrophobic dienophiles for electrocatalytic Diels‐Alder reactions.