Dai C, Xie Z, Qing X, Luo N, Wang C. DBU-mediated annulation of 2-aryl-3-nitro-2H-chromenes with 1,3-cyclohexanediones for the synthesis of benzofuro[2,3-c]chromenone derivatives.
Mol Divers 2019;
24:191-200. [PMID:
30905029 DOI:
10.1007/s11030-019-09939-2]
[Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 03/08/2019] [Indexed: 11/26/2022]
Abstract
The DBU-mediated annulations of 2-aryl-3-nitro-2H-chromenes with 1,3-cyclohexanediones have been developed. This reaction involves a highly efficient domino sequence consisting of regioselective intermolecular Michael addition, intramolecular nucleophilic addition and aromatization as key unit steps. The reaction appears to be general for a variety of 2-aryl-3-nitro-2H-chromenes and tolerates the presence of aromatic moieties with electron-withdrawing and electron-donating substituents. This transformation provides a straightforward synthetic protocol for constructing benzofuro[2,3-c]chromenone derivatives.
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