Carbocation Lewis Acid Catalyzed Redox-Neutral alpha-C(sp(3))H Arylation of Amines
文献类型：期刊论文
| 作者 | Zhang Qichao; Lu Jian; Luo Sanzhong |
| 刊名 | ACTA CHIMICA SINICA
 |
| 出版日期 | 2016-01-15 |
| 卷号 | 74期号:1页码:61-66 |
| 关键词 | carbocation Lewis acid redox-neutral reaction alpha-C(sp3)H arylation organocatalysis |
| 英文摘要 | The alpha-substituted nitrogen-containing heterocycles (N-heterocycles) like tetrahydroisoquinolines (THIQs) and piperidines are common in nature and are present as the key functional group in bioactive and pharmacologically active compounds. The two traditional approaches for the synthesis of alpha-substituted N-heterocycles are Pictet-Spengler condensation and hydrogenation of the alpha-substituted cyclic imines. Recently, direct C(sp(3))-H functionalization of N-heterocycles with various nucleophiles catalyzed by transition metal complex under the oxidants presents an atom-economic protocol without prior installation of activating group. However, new catalytic strategy or catalysts are still desirable in order to further address the use of excess oxidants and expensive transition metal complex. Stable carbocations, such as tritylium ions, have been widely used as organic Lewis acid catalysts and reagents in organic synthesis. In our studies, it was found that tritylium salts [Ph3C][BArF] (10 mol%) in situ generated by Ph3CBr (0.02 mmol) and NaBArF (0.02 mmol) could promote the three component redox-neutral alpha-arylation of amines reaction with tetrahydroisoquinoline 2 (0.3 mmol), aldehyde 3 (0.2 mmol) and indole 4 (0.3 mmol) in toluene (1.0 mL) to afford the desired alpha-substituted N-heterocyclic compounds 5 in good yields (up to 99% yield) at ambient temperature to 50 degrees C. To our satisfaction, a variety of differently substituted indoles 4a similar to 4i could work well with tetrahydroisoquinoline 2 and 2,6-dichlorobenzaldehyde 3a to provide the corresponding alpha-substituted N-heterocyclic compounds 5a similar to 5i in good to excellent yields at room temperature. When other substituted benzaldehydes 3b similar to 3f were used, the reactions could also proceed smoothly to give the compounds 5j similar to 5o with moderate yield (up to 66% yield) at 50 degrees C. Moreover, we have also developed redox-neutral a-arylation of tetrahydroisoquinoline 2 with other aromatic nucleophile such as substituted phenol, beta-naphthol and pyrrole under the optimal reaction conditions. Importantly, the model reaction, conducted in the presence of Na2CO3(1.0 equiv.) or 2,6-bis(tert-butyl) pyridine (0.5 equiv.) at room temperature in toluene also proceeded smoothly to give the desired adduct 5a with comparable yields (82% and 92% yield, respectively), which could exclude the possibility of free acid catalysis in this reaction. |
| 收录类别 | SCI |
| 语种 | 英语 |
| 源URL | [http://ir.iccas.ac.cn/handle/121111/35830]  |
| 专题 | 化学研究所_分子识别与功能实验室 |
| 作者单位 | Chinese Acad Sci, Inst Chem, CAS Key Lab Mol Recognit & Funct, BNLMS, Beijing 100190, Peoples R China |
| 推荐引用方式 GB/T 7714 | Zhang Qichao,Lu Jian,Luo Sanzhong. Carbocation Lewis Acid Catalyzed Redox-Neutral alpha-C(sp(3))H Arylation of Amines[J]. ACTA CHIMICA SINICA,2016,74(1):61-66. |
| APA | Zhang Qichao,Lu Jian,&Luo Sanzhong.(2016).Carbocation Lewis Acid Catalyzed Redox-Neutral alpha-C(sp(3))H Arylation of Amines.ACTA CHIMICA SINICA,74(1),61-66. |
| MLA | Zhang Qichao,et al."Carbocation Lewis Acid Catalyzed Redox-Neutral alpha-C(sp(3))H Arylation of Amines".ACTA CHIMICA SINICA 74.1(2016):61-66. |
入库方式： OAI收割
来源：化学研究所
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