FeCl 催化的α-氨基腈与炔烃的脱氰[4 + 2]环加成反应：批量和连续流过程中 2,4-二芳基喹啉的合成。

FeCl-Catalyzed Decyanative [4 + 2] Annulation of α-Aminonitriles with Alkynes: Access to 2,4-Diaryl Quinolines in Batch and Continuous-Flow Processes.

机构信息

Department of Chemistry, Faculty of Engineering and Technology, SRM Institute of Science and Technology, Kattankulathur 603 203, Chengalpattu District, Tamil Nadu, India.

Interdisciplinary Institute of Indian System of Medicine (IIISM), SRM Institute of Science and Technology, SRM Nagar, Kattankulathur 603 203, Chengalpattu District, Tamil Nadu, India.

出版信息

Org Lett. 2023 Jun 9;25(22):4086-4091. doi: 10.1021/acs.orglett.3c01306. Epub 2023 May 25.

DOI:10.1021/acs.orglett.3c01306

PMID:37229529

Abstract

FeCl-catalyzed decyanation of α-aminonitriles followed by a [4 + 2] annulation with terminal alkynes has been developed to synthesize 2,4-diaryl quinolines. A broad range of aniline, aldehyde, and arylacetylene derivatives were well tolerated to access 2,4-diaryl quinolines in moderate to good yields. The control experiment studies suggested that the reaction proceeds through a nonradical pathway involving Povarov-type [4 + 2] annulation from the generated iminium species. The synthetic application of this strategy (i) includes gram-scale synthesis and (ii) a continuous-flow process for a few representative compounds in a shorter reaction time (22 min) and (iii) worked well with styrene as a proof of concept.

摘要

氯化铁催化的α-氨基腈脱氰反应，接着与末端炔烃进行[4+2]环加成反应，合成了 2,4-二芳基喹啉。苯胺、醛和芳基乙炔衍生物的广泛范围都能耐受，以中等至良好的收率得到 2,4-二芳基喹啉。控制实验研究表明，反应通过非自由基途径进行，涉及从生成的亚胺物种进行 Povarov 型[4+2]环加成。该策略的合成应用（i）包括克级合成和（ii）在较短反应时间（22 分钟）内对几个代表性化合物的连续流过程，（iii）与苯乙烯一起很好地工作，作为概念验证。