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Li X, Liao LF, Ding LY, Chen CH, Liang C, Mo DL. Iron(III) and BF 3·OEt 2-Promoted O-Transfer Reaction of N-Aryl-α,β-Unsaturated Nitrones to Prepare Difluoroboron β-Ketoiminates. Org Lett 2024; 26:3060-3064. [PMID: 38552180 DOI: 10.1021/acs.orglett.4c00693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/20/2024]
Abstract
We described an iron(III) and BF3·OEt2-promoted oxygen transfer reaction of N-aryl-α,β-unsaturated nitrones to prepare various N,O-difluoroboron β-ketoiminates in good yields ranging from 24% to 87%. Control experiments revealed that the enaminone was the vital intermediate for the formation of N,O-difluoroboron β-ketoiminates, and iron(III) combined with BF3·OEt2 played as cocatalyst to promote the oxygen transfer reaction through intramolecular cyclization and N-O bond cleavage. More importantly, an estrone-derived N,O-difluoroboron β-ketoiminate was easily prepared in 40% yield from estrone in four steps.
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Affiliation(s)
- Xue Li
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources (Ministry of Education of China), Collaborative Innovation Center for Guangxi Ethnic Medicine, School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, 15 Yu Cai Road, Guilin 541004, China
| | - Lin-Fen Liao
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources (Ministry of Education of China), Collaborative Innovation Center for Guangxi Ethnic Medicine, School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, 15 Yu Cai Road, Guilin 541004, China
| | - Li-Yao Ding
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources (Ministry of Education of China), Collaborative Innovation Center for Guangxi Ethnic Medicine, School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, 15 Yu Cai Road, Guilin 541004, China
| | - Chun-Hua Chen
- Key Laboratory of Chemistry and Engineering of Forest Products, State Ethnic Affairs Commision, Guangxi Key Laboratory of Chemistry and Engineering of Forest Products, Guangxi Collaborative Innovation Center for Chemistry and Engineering of Forest Products, School of Chemistry and Chemical Engineering, Guangxi Minzu University, Nanning 530008, China
| | - Cui Liang
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources (Ministry of Education of China), Collaborative Innovation Center for Guangxi Ethnic Medicine, School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, 15 Yu Cai Road, Guilin 541004, China
| | - Dong-Liang Mo
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources (Ministry of Education of China), Collaborative Innovation Center for Guangxi Ethnic Medicine, School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, 15 Yu Cai Road, Guilin 541004, China
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Nong CM, Lv SN, Shi WM, Liang C, Su GF, Mo DL. Synthesis of 1,2,4-Oxadiazolines through Deoxygenative Cyclization of N-Vinyl-α,β-Unsaturated Nitrones with in Situ Generated Nitrile Oxides from Hydroxamoyl Chlorides. Org Lett 2023; 25:267-271. [PMID: 36583596 DOI: 10.1021/acs.orglett.2c04121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
A variety of 1,2,4-oxadiazoline derivatives were synthesized in moderate to good yields through a deoxygenative cyclization cascade reaction of N-vinyl-α,β-unsaturated nitrones and hydroxamoyl chlorides. Mechanistic studies revealed that the reaction underwent double additions of nitrile oxides to N-vinyl-α,β-unsaturated nitrones, sequential elimination, and intramolecular cyclization to afford 1,2,4-oxadiazolines. Alternatively, 1,2,5-oxadiazolines were also obtained as major products in i-PrOH solvent through [3 + 3] cycloaddition and selective [3,3]-rearrangement. Moreover, the prepared 1,2,4-oxadiazolines were easily converted to polysubstituted pyrroles under thermal conditions.
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Affiliation(s)
- Cai-Mei Nong
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, Collaborative Innovation Center for Guangxi Ethnic Medicine, School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, 15 Yu Cai Road, Guilin, 541004, China
| | - Si-Ning Lv
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, Collaborative Innovation Center for Guangxi Ethnic Medicine, School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, 15 Yu Cai Road, Guilin, 541004, China
| | - Wei-Min Shi
- School of Medicine, Guangxi University of Science and Technology, 257 Liu Shi Road, Liuzhou, 545006, China
| | - Cui Liang
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, Collaborative Innovation Center for Guangxi Ethnic Medicine, School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, 15 Yu Cai Road, Guilin, 541004, China
| | - Gui-Fa Su
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, Collaborative Innovation Center for Guangxi Ethnic Medicine, School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, 15 Yu Cai Road, Guilin, 541004, China
| | - Dong-Liang Mo
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, Collaborative Innovation Center for Guangxi Ethnic Medicine, School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, 15 Yu Cai Road, Guilin, 541004, China
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Chen H, Wei C, Pang GL, Liang C, Mo DL, Ma XP. Synthesis of N-Vinyl Cinnamaldehyde Nitrones through Atropisomeric Quinoxaline-Derived N, N, O-Ligand-Promoted Chan-Lam Reaction. Org Lett 2022; 24:6013-6017. [PMID: 35947787 DOI: 10.1021/acs.orglett.2c02288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A type of quinoxaline-derived tridentate N,N,O-ligand was synthesized in good to excellent yields over three steps through iodination of 2-aryl indoles, sequential Kornblum-type oxidation with DMSO, and capture by 1,2-diaminobenzenes. The prepared atropisomeric N,N,O-ligand was successfully applied in the synthesis of N-vinyl cinnamaldehyde nitrones as only Z-isomers in good yields through the Chan-Lam reaction. The method features an easily accessed tunable tridentate N,N,O-ligand, broad substrate scope, good functional group tolerance, and high Z-isomer for N-vinyl nitrones.
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Affiliation(s)
- Hao Chen
- College of Pharmacy, Guilin Medical University, 1 Zhi Yuan Road, Guilin 541199, China.,State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, Ministry of Science and Technology of China; School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, 15 Yu Cai Road, Guilin 541004, China
| | - Cui Wei
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, Ministry of Science and Technology of China; School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, 15 Yu Cai Road, Guilin 541004, China
| | - Guang-Li Pang
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, Ministry of Science and Technology of China; School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, 15 Yu Cai Road, Guilin 541004, China
| | - Cui Liang
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, Ministry of Science and Technology of China; School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, 15 Yu Cai Road, Guilin 541004, China
| | - Dong-Liang Mo
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, Ministry of Science and Technology of China; School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, 15 Yu Cai Road, Guilin 541004, China
| | - Xiao-Pan Ma
- College of Pharmacy, Guilin Medical University, 1 Zhi Yuan Road, Guilin 541199, China
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4
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Bi HY, Wu QY, Zhou XM, Xu HJ, Liang C, Mo DL, Ma XP. Chan-Lam Reaction and Lewis Acid Promoted 1,3-Rearrangement of N-O Bonds to Prepare N-(2-Hydroxyaryl)pyridin-2-ones. Org Lett 2022; 24:4675-4679. [PMID: 35713172 DOI: 10.1021/acs.orglett.2c01827] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We describe the difunctionalization of arylboronic acids to prepare various N-(2-hydroxyaryl)pyridin-2-ones in good yields using N-hydroxypyridin-2-ones as the oxygen and nitrogen sources through a copper(II)-catalyzed Chan-Lam reaction and subsequent BF3-promoted selective 1,3-rearrangement of N-O bond in a one-pot procedure. Mechanistic studies reveal that the 1,3-rearrangement selectivity is controlled by the formation of the key aryloxypyridinium salt. The obtained products are easily converted to various useful pyridin-2-one scaffolds.
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Affiliation(s)
- Hong-Yan Bi
- College of Pharmacy, Guilin Medical University, 1 Zhi Yuan Road, Guilin 541199, China.,State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, Collaborative Innovation Center for Guangxi Ethnic Medicine, School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, 15 Yu Cai Road, Guilin 541004, China
| | - Qing-Yan Wu
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, Collaborative Innovation Center for Guangxi Ethnic Medicine, School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, 15 Yu Cai Road, Guilin 541004, China
| | - Xiao-Mei Zhou
- College of Pharmacy, Guilin Medical University, 1 Zhi Yuan Road, Guilin 541199, China
| | - Hui-Juan Xu
- College of Pharmacy, Guilin Medical University, 1 Zhi Yuan Road, Guilin 541199, China
| | - Cui Liang
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, Collaborative Innovation Center for Guangxi Ethnic Medicine, School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, 15 Yu Cai Road, Guilin 541004, China
| | - Dong-Liang Mo
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, Collaborative Innovation Center for Guangxi Ethnic Medicine, School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, 15 Yu Cai Road, Guilin 541004, China
| | - Xiao-Pan Ma
- College of Pharmacy, Guilin Medical University, 1 Zhi Yuan Road, Guilin 541199, China
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WANG W, Zou PS, PANG L, Pan C, Mo DL, SU GF. Recent Advances on the Synthesis of 2,3-Fused Quinazolinones. Org Biomol Chem 2022; 20:6293-6313. [DOI: 10.1039/d2ob00778a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
As one of the most important structural units in pharmaceuticals and medicinal chemistry, quinazolinone and its derivatives exhibit a wide range of biological and pharmacological activities, including anti-inflammatory, antitubercular, antiviral,...
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