Kitamura Y, Murata Y, Iwai M, Matsumura M, Yasuike S. Palladium-Catalyzed C-H Arylation of Benzofurans with Triarylantimony Difluorides for the Synthesis of 2-Arylbenzofurans.
Molecules 2020;
26:E97. [PMID:
33379315 PMCID:
PMC7795347 DOI:
10.3390/molecules26010097]
[Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2020] [Revised: 12/23/2020] [Accepted: 12/25/2020] [Indexed: 11/23/2022] Open
Abstract
Pd-catalyzed regioselective C-H arylation is a useful tool for the chemical modification of aromatic heterocycles and 2-arylbenzofuran derivatives are of interest as biologically active substances. Herein, the reaction of triarylantimony difluorides with benzofurans under aerobic conditions in 1,2-DCE, using 5 mol% Pd (OAc)2 and 2 eq. of CuCl2 at 80 °C, produced a variety of 2-arylbenzofurans in moderate-to-high yields. The reaction is sensitive to the electronic nature of the substituents on the benzene ring of the triarylantimony difluorides: an electron-donating group showed higher reactivity than an electron-withdrawing group. Single crystal X-ray analysis of tri(p-methylphenyl) antimony difluoride revealed that the central antimony atom exhibits trigonal bipyramidal geometry.
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