Enantioselective N-Heterocyclic Carbene Catalysis by the Umpolung of ,-Unsaturated Ketones
Enantioselective N-Heterocyclic Carbene Catalysis by the Umpolung of ,-Unsaturated Ketones
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DOI：
10.1002/anie.201510106
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发表时间：
2016-02-24
影响因子：
16.6
通讯作者：
Lupton, David W.
中科院分区：
文献类型：
--
作者：
Nakano, Yuji;Lupton, David W.
N-杂环卡宾催化烯酮形成β-阴离子中间体已被用于2-芳基丙酸酯的对映选择性合成。该反应可以使用纯手性 4-MeOC6H4 吗啉酮催化剂实现，这是通过 β-不饱和酮的反极性进行对映选择性催化的第一个例子。该反应产率高，具有鲁棒性和合理的通用性。提出了一种机制，其中使用六氟异丙醇或形成的萘酚产物实现对映决定质子化。
N-Heterocyclic carbene-catalyzed formation of -anionic intermediates from enones has been employed in the enantioselective synthesis of 2-aryl propionates. The reaction was achievable using a homochiral 4-MeOC6H4 morpholinone catalyst allowing the first example of enantioselective catalysis by umpolung of ,-unsaturated ketones. The reaction is high yielding, and shows robustness with reasonable generality. A mechanism is proposed in which the enantiodetermining protonation is achieved using either hexafluoroisopropanol or the formed naphthol product.