A series of 2- and 3-aryl substituted indoles and two 1,3,4,5-tetrahydropyrano[4,3-b]indoles were synthesized from indole and 5-methoxyindole. The 2-aryl indoles were synthesized from the 1-(phenylsulfonyl)indole derivatives using magnesiation followed by iodination. The 2-iodinated compounds were then subjected to Suzuki-Miyaura reactions. In addition, the 3-aryl indoles were made from the corresponding 3-bromoindoles using Suzuki-Miyaura reactions. The 1,3,4,5-tetrahydropyrano[4,3-b]indoles were also synthesized from 1-(phenylsulfonyl)indole by magnesiation followed by treatment with allylbromide. The product was then converted into [2-allyl-1-(phenylsulfonyl)-1H-indol-3-yl]methanol which upon exposure to Hg(OAc)(2) and NaBH(4) afforded tetrahydropyrano[4,3-b]indoles. A number of the 2- and 3-aryl indoles displayed noteworthy antimicrobial activity, with compound 13a displaying the most significant activity (3.9 microg/mL) against the Gram-positive micro-organism Bacillus cereus.
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http://dx.doi.org/10.1016/j.bmcl.2009.07.091 | DOI Listing |
Front Chem
November 2024
Endocrinology and Metabolism Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran.
Introduction: The increasing prevalence of antibiotic-resistant pathogens necessitates the urgent development of new antibacterial agents. Concurrently, synthetic chemistry is moving towards more sustainable practices that minimize environmental impact. This study aims to synthesize 3-aryl-2-benzo[b][1,4]oxazin-2-one derivatives, including the natural product cephalandole A, using a sustainable approach that avoids metal catalysts.
View Article and Find Full Text PDFBioorg Chem
December 2024
State Key Laboratory of Fine Chemicals, Department of Pharmaceutical Engineering, School of Chemical Engineering, Dalian University of Technology, 2 Linggong Road, Dalian 116024, PR China. Electronic address:
A series of 3-(2-trifluoromethyl-3-aryl-4H-chromen-4-yl)-1H-indoles (5-1 to 5-29) were developed and characterized. Most of compounds were found to be potent for inhibiting the production of NO in LPS-induced RAW264.7 cells, of which 3-(3-(4-chlorophenyl)-6-methoxy-2-(trifluoromethyl)-4H-chromen-4-yl)-1H-indole (5-25) was the most optimal (IC = 4.
View Article and Find Full Text PDFJ Org Chem
August 2024
Beijing National Laboratory for Molecular Sciences (BNLMS), CAS Key Laboratory of Molecular Recognition and Function, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
We present here a new method for the synthesis of 2-substituted-3-aryl benzoheterocycles through a more challenging constrained [1,5]-type Friedel-Crafts reaction/rearrangement and aromatization process. By using the readily available 2-aryoxy-1,3-indandiones and 2-arylamino-1,3-indandiones, a range of 2-substituted-3-aryl benzofurans and indoles were prepared in good to excellent yields (yields up to 86%) under the catalysis of CFSOH or Sm(OTf). Compared with previous methods for constructing similar structures, this approach offers several advantages, including the use of easily accessible starting materials, mild reaction conditions, high yield, excellent regio- and diastereoselectivity, and a broad substrate scope.
View Article and Find Full Text PDFOrg Biomol Chem
July 2024
School of Perfume and Aroma Technology, Shanghai Institute of Technology, Shanghai 201418, P. R. China.
An efficient and metal-free method for the synthesis of 3-aryl pyrido[1,2-]indoles from aryne intermediates and 2-pyridinyl-substituted -QMs was successfully developed under ambient conditions. The reaction offered a novel and practical protocol to access some diverse functional molecules in good to excellent yields. The proposed mechanism indicated that the reaction proceeded a formal [3 + 2] cycloaddition step.
View Article and Find Full Text PDFJ Org Chem
December 2023
Mulliken Center for Theoretical Chemistry University of Bonn Beringstr. 4, 53115 Bonn, Germany.
Herein, we report a polyphosphoric acid (PPA)-mediated divergent metal-free operation to access a diverse collection of 3-(indol-2-yl)quinoxalin-2-ones and 4-(benzimidazol-2-yl)-3-methylcinnolines in moderate to excellent overall yields. The described process involves two distinct, and competing rearrangements of 3-(methyl(2-phenylhydrazono)methyl)quinoxalin-2-ones, namely [3,3]-sigmatropic Fischer rearrangement with the formation of an indole ring to produce 3-(indol-2-yl)-quinoxalin-2-ones, and Mamedov rearrangement with simultaneous construction of benzimidazole and cinnoline rings to form the new biheterocyclic system─4-(benzimidazol-2-yl)-3-methylcinnolines. The reaction mechanism of both rearrangement channels is explored by extensive dispersion-corrected DFT calculations.
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