Key Laboratory of Chemical Genomics, School of Chemical Biology and Biotechnology, Peking University, Shenzhen Graduate School, Shenzhen 518055, China.
Chem Commun (Camb). 2013 Dec 7;49(94):11098-100. doi: 10.1039/c3cc46757k.
An enantioselective organocatalytic process for the one-step synthesis of poly-substituted 1,2,4-triazolines is reported. The heterocycle formation is believed to go through a step-wise mechanism of nucleophilic addition of an azlactone to an azodicarboxylate in the presence of an organic base catalyst, followed by a TMSCHN2 mediated heterocyclization. Both theoretical calculations and experimental evidence suggest the pre-organization of the transition state for the chirality determining step via a unique 7-membered intramolecular hydrogen bonding.
报道了一种对映选择性的有机催化方法，用于一步合成多取代的 1,2,4-三唑啉。杂环的形成被认为是通过在有机碱催化剂存在下，氮丙啶二羧酸酯与氮丙啶酮的亲核加成，然后通过 TMSCHN2 介导的杂环化反应来实现的。理论计算和实验证据都表明，通过独特的 7 元分子内氢键，对决定手性的过渡态进行预组织。
