Martelli Lorena S R, Furniel Lucas G, Santiago Pedro H O, Ellena Javier, Corrêa Arlene G
Centre of Excellence for Research in Sustainable Chemistry, Department of Chemistry, Federal University of São Carlos, São Carlos, São Paulo 13565-905, Brazil.
São Carlos Institute of Physics, University of São Paulo, São Carlos, São Paulo 13563-120, Brazil.
ACS Omega. 2025 Apr 23;10(17):18017-18028. doi: 10.1021/acsomega.5c01416. eCollection 2025 May 6.
This work reports the first synthesis of Δ-pyrrolines promoted by visible light under continuous flow, achieved through the formal (3 + 2)-cycloaddition of 2-azirines to enones. A total of 22 examples of trisubstituted Δ-pyrrolines were prepared in only 30 min of residence time, with 41-93% yield and diastereomeric ratios up to 7:3. Furthermore, continuous flow conditions were also effective when chalcones were used as starting materials, leading to the formation of 7 tetrasubstituted pyrroles with an overall yield ranging from 12 to 47%, via a photocatalyzed cycloaddition-oxidation sequence.
这项工作报道了在连续流动条件下可见光促进的Δ-吡咯啉的首次合成，该合成通过2-氮杂环丙烯与烯酮的形式上的（3+2）环加成反应实现。仅在30分钟的停留时间内就制备了总共22个三取代Δ-吡咯啉的实例，产率为41-93%，非对映体比例高达7:3。此外，当使用查耳酮作为起始原料时，连续流动条件也有效，通过光催化环加成-氧化序列，生成了7个四取代吡咯，总产率在12%至47%之间。
