Synthesis, Table of Contents Synthesis 2025; 57(14): 2197-2206DOI: 10.1055/a-2591-8986 paper Synthesis of Benzofuro[3,2-c]isoquinolines through Anionic Intramolecular Cyclization Bo Yang a Department of Chemistry, University of Science and Technology of China, Hefei 230026, P. R. of China , Peng-Fei Dai a Department of Chemistry, University of Science and Technology of China, Hefei 230026, P. R. of China , Jian-Ping Qu∗ b School of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing 211816, P. R. of China , Yan-Biao Kang∗ a Department of Chemistry, University of Science and Technology of China, Hefei 230026, P. R. of China› Author AffiliationsRecommend Article Abstract Buy Article All articles of this category Abstract Benzofuro[3,2-c]isoquinolines are among the typical tetraheterocycles. The synthesis of benzofuro[3,2-c]isoquinoline derivatives in the presence of a catalytic amount of KOH has been developed. A variety of substituents could be tolerated. The base (KOH) works as a catalyst. A gram-scale synthesis was performed. Control experiments confirmed that a cascade anionic annulation is involved rather than a radical cyclization. Key words Key wordsbase - cascade annulation - tetraheterocycles - benzofuro[3,2-c]isoquinolines - transition-metal-free - catalyst free Full Text References References 1 Marshall CM, Federice JG, Bell CN, Cox PB, Njardarson JT. J. Med. Chem. 2024; 67: 11622 2a Stępień M, Gońka E, Żyła M, Sprutta N. Chem. Rev. 2017; 117: 3479 2b Kerru N, Gummidi L, Maddila S, Gangu KK, Jonnalagadda SB. Molecules 2020; 25: 1909 2c Martins P, Jesus J, Santos S, Raposo LR, Roma-Rodrigues C, Baptista PV, Fernandes AR. Molecules 2015; 20: 16852 2d Taylor AP, Robinson RP, Fobian YM, Blakemore DC, Jones LH, Fadeyi O. Org. Biomol. Chem. 2016; 14: 6611 2e Borissov A, Maurya YK, Moshniaha L, Wong W.-S, Żyła-Karwowska M, Stępień M. Chem. Rev. 2022; 122: 565 3a Kalugin VE, Shestopalov AM. Tetrahedron Lett. 2011; 52: 1557 3b Hsin L.-W, Chen C.-W, Chang L.-T. J. Chin. Chem. Soc. 2005; 52: 339 3c Cheng C.-Y, Hsin L.-W, Tsai M.-C, Schmidt WK, Smith C, Tam SW. J. Med. Chem. 1994; 37: 3121 3d Jagtap P, Roy A, Williams W. US Patent 7393955B2, 2008 3e Kim S, Park J, Joshi DR, Lee NK, Pham HL. B, Chung LK, Kang M, Kim Y, Kim I, Lee J. Dyes Pigm. 2022; 206: 110584 3f Chaban TI, Matiichuk YE, Horishny VY, Chaban IG, Matiychuk VS. Russ. J. Org. Chem. 2020; 56: 813 3g Pal S, Choudhary D, Jainth M, Kumar S, Tiwari RK, Verma AK. J. Org. Chem. 2016; 81: 9356 4 Béres M, Timári G, Hajós G. Tetrahedron Lett. 2002; 43: 6035 5 Zhu D, Wu Z, Luo B, Du Y, Liu P, Chen Y, Hu Y, Huang P, Wen S. Org. Lett. 2018; 20: 4815 6 Yu Z, Zhang Y, Tang J, Zhang L, Liu Q, Li Q, Gao G, You J. ACS Catal. 2020; 10: 203 7a Shan X.-H, Yang B, Zheng H.-X, Qu J.-P, Kang Y.-B. Org. Lett. 2018; 20: 7898 7b Shan X.-H, Yang B, Qu J.-P, Kang Y.-B. Chem. Commun. 2020; 56: 4063 7c Chen Y.-Z, Chen Y.-M, Hu Y, Qu J.-P, Kang Y.-B. Org. Lett. 2023; 25: 7518 7d Li Y.-W, Zheng H.-X, Yang B, Shan X.-H, Qu J.-P, Kang Y.-B. Org. Lett. 2020; 22: 4553 8 Zheng H.-X, Shan X.-H, Qu J.-P, Kang Y.-B. Org. Lett. 2018; 20: 3310 9 Shan X.-H, Zheng H.-X, Yang B, Tie L, Fu J.-L, Qu J.-P, Kang Y.-B. Nat. Commun. 2019; 10: 908 10 Yang Q, Li Y, Yang J.-D, Liu Y, Zhang L, Luo S, Cheng J.-P. Angew. Chem. Int. Ed. 2020; 59: 19282 Supplementary Material Supplementary Material Supporting Information
