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Liao S, Xu H, Yang B, Wang J, Zhou X, Lin X, Liu Y. Gold-catalyzed oxidation of terminal alkynes to glyoxals and their reactions with 2-phenylimidazo[1,2- a]pyridines: one-pot synthesis of 1,2-diones. Org Biomol Chem 2021; 19:8735-8739. [PMID: 34476433 DOI: 10.1039/d1ob01507a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A novel one-pot protocol for the convenient and efficient synthesis of (2-phenylimidazo[1,2-a]pyridin-3-yl)alkane-1,2-diones (3) in good yields (32-88%) from 2-phenylimidazo[1,2-a]pyridines (1) and terminal alkynes (2) has been established with a wide range of substrate scope. A tandem reaction sequence containing gold-catalyzed double oxidations of terminal alkynes to generate glyoxals, nucleophilic addition of 2-phenylimidazo[1,2-a]pyridines to glyoxals to yield α-hydroxyl ketones, and oxygenation of the α-hydroxyl ketones to afford the final products 3 under air atmosphere is involved in this method. Simple operation, mild reaction conditions, and widely available substrates make this strategy more affordable.
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Affiliation(s)
- Shengrong Liao
- CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, Research Center for Marine Microbes, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China. .,Sanya Institute of Oceanology, SCSIO, Yazhou Scientific Bay, Sanya 572000, China.,Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China
| | - Huayan Xu
- CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, Research Center for Marine Microbes, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China.
| | - Bin Yang
- CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, Research Center for Marine Microbes, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China.
| | - Junfeng Wang
- CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, Research Center for Marine Microbes, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China. .,Sanya Institute of Oceanology, SCSIO, Yazhou Scientific Bay, Sanya 572000, China
| | - Xuefeng Zhou
- CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, Research Center for Marine Microbes, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China. .,Sanya Institute of Oceanology, SCSIO, Yazhou Scientific Bay, Sanya 572000, China
| | - Xiuping Lin
- CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, Research Center for Marine Microbes, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China.
| | - Yonghong Liu
- CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, Research Center for Marine Microbes, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China. .,Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China
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Nandwana N, Patel OPS, Srivathsa MR, Kumar A. Dual Role of Glyoxal in Metal-Free Dicarbonylation Reaction: Synthesis of Symmetrical and Unsymmetrical Dicarbonyl Imidazoheterocycles. ACS OMEGA 2019; 4:10140-10150. [PMID: 31460106 PMCID: PMC6648449 DOI: 10.1021/acsomega.9b00716] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 05/22/2019] [Indexed: 05/28/2023]
Abstract
A practical and efficient method has been developed for the dicarbonylation of imidazoheterocycles using glyoxals as dicarbonyl precursors under metal-free conditions in acetic acid. A series of symmetrical and unsymmetrical dicarbonyl imidazoheterocycles was synthesized in good yields. Aryl and alkyl glyoxals also demonstrated excellent reactivity under similar reaction conditions and delivered corresponding dicarbonyl imidazoheterocycles in high yields. It is believed that the glyoxal plays a dual role both as a dicarbonyl source and as an oxidant in this transformation. A probable mechanistic pathway has been proposed based on control experiments and electrospray ionization high-resolution mass spectrometry analysis.
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