Graduate School of Pharmaceutical Sciences, Kyoto University.
Research Foundation ITSUU Laboratory.
Chem Pharm Bull (Tokyo). 2022;70(5):359-361. doi: 10.1248/cpb.c22-00076.
Despite the long history of the ene reaction between 1,2,4-triazoline-3,5-diones (TADs) and alkenes, its efficiency has always been hampered by competing side reactions, including the overreaction of ene adducts. In this communication, we demonstrate that this inherent limitation can be overcome by using 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) as the solvent. HFIP uniquely facilitates the desired azo-ene process between alkene with TADs presumably through hydrogen-bonding interactions. In addition to TADs, diethyl azodicarboxylate is a competent azo compound that undergoes a sluggish ene reaction with terminal alkenes.
尽管 1,2,4-三唑啉-3,5-二酮（TADs）与烯烃之间的 ene 反应具有悠久的历史，但由于存在竞争的副反应，包括 ene 加合物的过度反应，其效率一直受到阻碍。在本通讯中，我们证明通过使用 1,1,1,3,3,3-六氟-2-丙醇（HFIP）作为溶剂可以克服这种固有的限制。HFIP 通过氢键相互作用独特地促进了烯烃与 TAD 之间所需的偶氮-ene 反应。除了 TADs，二乙基偶氮二羧酸酯是一种有效的偶氮化合物，它与末端烯烃进行缓慢的 ene 反应。
