Concise Synthesis of Polycyclic Indoline Scaffolds through an InIII‐Catalyzed Formal [4+2] Annulation of 2, 3‐Disubstituted Indoles with o‐Aminobenzyl Alcohols. Issue 18 (12th May 2017)

• Record Type: Journal Article
• Authors: Luo, Mupeng; Chen, Jianxin; Yu, Linqian; Wei, Wanguo
• Is Part Of: European journal of organic chemistry. Issue 18(2013)
• Page Start: 2652
• Page End: 2660
• Publication Date: 2017-05-12
• Subjects: Nitrogen heterocycles -- Fused‐ring systems -- Cycloaddition -- Diastereoselectivity -- Indium; Chemistry, Organic -- Periodicals; Organic compounds -- Synthesis -- Periodicals; Bioorganic chemistry -- Periodicals; Chemistry, Physical organic -- Periodicals; 547
• DOI: 10.1002/ejoc.201700432
• Languages: English
• ISSNs: 1434-193X

Abstract

Abstract : A concise indium(III)‐catalyzed annulation of 2, 3‐disubstituted indoles with o ‐aminobenzyl alcohols is reported. The in situ generated aza‐ ortho ‐quinone methides (aza‐ o QMs) were efficiently trapped by diverse carbazoles in a formal [4+2] cycloaddition reaction catalyzed by indium(III) triflate, which provided rapid access to bridged polycyclic indoline alkaloid skeletons. Abstract : The cycloaddition of the in situ generated aza‐ ortho ‐quinone methides (aza‐ o QMs) with 2, 3‐disubstituted indoles leads to the bridged polycyclic indoline alkaloid skeletons through a formal [4+2] annulation. The products were obtained in moderate to excellent yields with high regioselectivity in the presence of a catalytic amount of indium(III) triflate. DCE = 1, 2‐dichloroethane; OTf = trifluoromethanesulfonate.