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Sharma M, Tamanna, Chauhan P. Asymmetric Synthesis of Hydrophenanthrenones Bearing Multiple Stereogenic Centers via Squaramide-Catalyzed Domino 1,4-/1,4-Addition Desymmetrization Sequence. Org Lett 2023; 25:7911-7916. [PMID: 37882793 DOI: 10.1021/acs.orglett.3c03167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2023]
Abstract
An unprecedented stereoselective route for procuring tetrahydrophenanthren-2(1H)-ones bearing up to five contiguous stereogenic centers has been accomplished. A bifunctional squaramide enables a domino 1,4-/1,4-addition desymmetrization reaction sequence between the newly developed β-nitrostyrene-tethered 2,5-cyclohexadienones and trisubstituted enolizable nucleophiles to provide direct access to the polyfunctionalized hydrophenanthren-2(1H)-ones in excellent enantio- (up to >99%) and diastereoselectivity (up to >20:1). By using a psedoenantiomeric squaramide, the enantiomers of hydrophenanthrene derivatives were also accessed with excellent stereocontrol.
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Affiliation(s)
- Manisha Sharma
- Department of Chemistry, Indian Institute of Technology Jammu, NH-44, Nagrota Bypass, Jammu, 181221 Jammu and Kashmir, India
| | - Tamanna
- Department of Chemistry, Indian Institute of Technology Jammu, NH-44, Nagrota Bypass, Jammu, 181221 Jammu and Kashmir, India
| | - Pankaj Chauhan
- Department of Chemistry, Indian Institute of Technology Jammu, NH-44, Nagrota Bypass, Jammu, 181221 Jammu and Kashmir, India
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An C, Bi H, Wang SR. Aromatic Homo-Nazarov-Type Cyclization of Benzonorcaradienes: Stereoselective Synthesis of Hydrochrysenes. J Org Chem 2023; 88:2670-2674. [PMID: 36753613 DOI: 10.1021/acs.joc.3c00052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
Formal homo-Nazarov cyclization of benzonorcaradienes produced by intramolecular hydroarylation of arylated alkynylcyclopropanes promoted by TfOH has been described, providing stereoselective access to highly substituted hydrochrysenes. An unprecedented 1,2-acyl migration occurred for the 2-heteroaroyl substrates, thus giving the same products as their 3-heteroaroyl analogs. Moreover, these products could be readily oxidized by air to fully π-conjugated chrysenes after decarboxylation.
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Affiliation(s)
- Caiyun An
- Chang-Kung Chuang Institute, School of Chemistry and Molecular Engineering, East China Normal University, 500 Dongchuan Lu, Shanghai 200241, China
| | - Hongyan Bi
- Chang-Kung Chuang Institute, School of Chemistry and Molecular Engineering, East China Normal University, 500 Dongchuan Lu, Shanghai 200241, China
| | - Sunewang R Wang
- Chang-Kung Chuang Institute, School of Chemistry and Molecular Engineering, East China Normal University, 500 Dongchuan Lu, Shanghai 200241, China.,Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, East China Normal University, 500 Dongchuan Lu, Shanghai 200241, China
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Li LP, Han JQ, Yang F, Wu X, Xie JH, Zhou QL. Total Synthesis of the Alleged Structure of (+)-Fimbricalyxoid A. Org Lett 2022; 24:3477-3481. [PMID: 35522037 DOI: 10.1021/acs.orglett.2c01076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
An enantioselective total synthesis of the alleged structure of (+)-fimbricalyxoid A is reported. The synthetic strategy features a pyridine-N-oxidate-mediated SN2' reaction to introduce an oxygen functionality at position C3 of the A-ring and a sequential three-step process via the cleavage of the C-O bonds and hemiketalization to form the 3,20-oxybridge. With this strategy, the target molecule was synthesized in 19% overall yield and 12 steps from our previously synthesized cis-fused octahydrophenanthrene (+)-6.
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Affiliation(s)
- Lin-Ping Li
- State Key Laboratory and Institute of Elemento-Organic Chemistry, Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University, Tianjin 300071, China
| | - Jia-Qi Han
- State Key Laboratory and Institute of Elemento-Organic Chemistry, Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University, Tianjin 300071, China
| | - Fan Yang
- State Key Laboratory and Institute of Elemento-Organic Chemistry, Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University, Tianjin 300071, China
| | - Xiong Wu
- State Key Laboratory and Institute of Elemento-Organic Chemistry, Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University, Tianjin 300071, China
| | - Jian-Hua Xie
- State Key Laboratory and Institute of Elemento-Organic Chemistry, Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University, Tianjin 300071, China.,Haihe Laboratory of Sustainable Chemical Transformations, Tianjin 300070, China
| | - Qi-Lin Zhou
- State Key Laboratory and Institute of Elemento-Organic Chemistry, Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University, Tianjin 300071, China.,Haihe Laboratory of Sustainable Chemical Transformations, Tianjin 300070, China
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