Synthesis of 2,3-Dihydro-4-pyridones, 4-Quinolones, and 2,3-Dihydro-4-azocinones by Visible-Light Photocatalytic Aerobic Dehydrogenation
Synthesis of 2,3-Dihydro-4-pyridones, 4-Quinolones, and 2,3-Dihydro-4-azocinones by Visible-Light Photocatalytic Aerobic Dehydrogenation
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DOI：
10.1002/ejoc.201900584
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发表时间：
2020-03-15
影响因子：
2.8
通讯作者：
Opatz, Till
中科院分区：
文献类型：
--
作者：
Sevenich, Adrian;Mark, Paulina Sophie;Opatz, Till
采用可见光介导光氧化催化4-哌啶酮和2,3-二氢-4-喹诺酮的好氧脱氢反应合成了2,3-二氢-4-吡酮和4-喹诺酮。该方法使用氧作为廉价的末端氧化剂，罗丹明6G作为易于获得的有机光催化剂，在温和和环保的条件下，以高达89%的收率合成了环胺酮，并具有很高的官能团耐受性。该工艺可以扩展到通过[2+2]环加成/扩环顺序在伸缩单釜反应中获得2,3-二氢-4-偶氮酮，收率高达62%。因此，在相同的一般转化上，开发了一种合成三种不同类型n -杂环的方案。
The synthesis of 2,3-dihydro-4-pyridones and 4-quinolones was realized by visible-light mediated photoredox-catalyzed aerobic dehydrogenation of 4-piperidones and 2,3-dihydro-4-quinolones. This method enables the synthesis of cyclic enaminones in up to 89 % yield under mild and eco-friendly conditions and with a high tolerance of functional groups using oxygen as an inexpensive terminal oxidant and rhodamine 6G as a readily available organic photocatalyst. The process can be extended to access 2,3-dihydro-4-azocinones in up to 62 % yield via a [2+2] cycloaddition/ring-expansion sequence in a telescoping one-pot reaction. Hence, a protocol for the synthesis of three different types of N-heterocycles was developed on the same general transformation.