Evolution of the Dearomative Functionalization of Activated Quinolines and Isoquinolines: Expansion of the Electrophile Scope
Evolution of the Dearomative Functionalization of Activated Quinolines and Isoquinolines: Expansion of the Electrophile Scope
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DOI：
10.1002/ange.202204682
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发表时间：
2022-05-13
影响因子：
16.6
通讯作者：
Donohoe，Timothy J.
中科院分区：
文献类型：
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作者：
Kischkewitz，Marvin;Marinic，Bruno;Donohoe，Timothy J.
在这里，我们公开了一种温和的协议，用于喹啉和异喹啉盐的还原官能化。反应在不含过渡金属的条件下进行，在催化剂负载量很低(0.01 %)的铑催化下进行，并使用廉价的甲酸作为末端还原剂。许多亲电性物质，包括烯酮、亚胺、不饱和酯和砜、β-硝基苯乙烯和醛，都会被原位形成的烯胺类物质截留，形成各种取代的四氢(异)喹啉。对于喹啉和异喹啉，亲电分子分别结合在C-3和C-4位置，提供了在亲电或亲核芳香族取代中不受欢迎的取代模式。最后，这种反应性被用来促进三种类型的环化反应，产生形式[3+3]或[4+2]环加成的复杂多环产物。
Herein we disclose a mild protocol for the reductive functionalisation of quinolinium and isoquinolinium salts. The reaction proceeds under transition‐metal‐free conditions as well as under rhodium catalysis with very low catalyst loadings (0.01 mol %) and uses inexpensive formic acid as the terminal reductant. A wide range of electrophiles, including enones, imides, unsaturated esters and sulfones, β‐nitro styrenes and aldehydes are intercepted by the in situ formed enamine species forming a large variety of substituted tetrahydro(iso)quinolines. Electrophiles are incorporated at the C‐3 and C‐4 position for quinolines and isoquinolines respectively, providing access to substitution patterns which are not favoured in electrophilic or nucleophilic aromatic substitution. Finally, this reactivity was exploited to facilitate three types of annulation reactions, giving rise to complex polycyclic products of a formal [3+3] or [4+2] cycloaddition.