Expanding the Chiral Monoterpene Pool: Enantioselective Diels–Alder Reactions of α-Acyloxy Enones
作者:Skyler D. Mendoza、Michael Rombola、Yujia Tao、Stephan J. Zuend、Roland Götz、Martin J. McLaughlin、Sarah E. Reisman
DOI:10.1021/acs.orglett.2c01343
日期:2022.6.3
α-acyloxy enones has been developed to synthesize chiral oxidized cyclohexenes. Yttrium(III) triflate, in conjunction with a chiral pyridinebisimidazoline (PyBim) ligand, was found to catalyze the asymmetric [4 + 2] cycloaddition with a variety of dienes and α-acyloxy enone dienophiles. Using this method, terpinene-4-ol, a key intermediate in the synthesis of commercial herbicide cinmethylin, can be prepared
已经开发了 α-酰氧基烯酮的对映选择性 Diels-Alder (DA) 反应来合成手性氧化环己烯。发现三氟甲磺酸钇 (III) 与手性吡啶双咪唑啉 (PyBim) 配体一起催化与各种二烯和 α-酰氧基烯酮亲二烯体的不对称 [4 + 2] 环加成反应。使用该方法,可通过四步异戊二烯制备商业除草剂cinmethylin的关键中间体terpinene-4-ol。动力学数据和 NMR 研究的结合支持了一种机制,该机制涉及亲二烯体与钇催化剂的可逆结合,然后与二烯环加成作为速率决定步骤。