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Dixon GJ, Rodriguez MR, Chong TG, Kim KY, Downey CW. Synthesis of β,β-Disubstituted Styrenes via Trimethylsilyl Trifluoromethanesulfonate-Promoted Aldehyde-Aldehyde Aldol Coupling-Elimination. J Org Chem 2022; 87:14846-14854. [PMID: 36239694 DOI: 10.1021/acs.joc.2c01458] [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
In the presence of trimethylsilyl trifluoromethanesulfonate (TMSOTf) and 2,6-lutidine, α,α-disubstituted aldehydes condense with electron-rich aromatic aldehydes to yield β,β-disubstituted styrenes. More electron-rich aromatic aldehydes react more rapidly and in higher yield. Preliminary results suggest that the reaction may proceed via the ionization and formal deformylation of an aldol intermediate.
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Affiliation(s)
- Grant J Dixon
- Department of Chemistry, University of Richmond, 138 UR Drive, Richmond, Virginia USA 23173, United States
| | - Michael R Rodriguez
- Department of Chemistry, University of Richmond, 138 UR Drive, Richmond, Virginia USA 23173, United States
| | - Tyler G Chong
- Department of Chemistry, University of Richmond, 138 UR Drive, Richmond, Virginia USA 23173, United States
| | - Kevin Y Kim
- Department of Chemistry, University of Richmond, 138 UR Drive, Richmond, Virginia USA 23173, United States
| | - C Wade Downey
- Department of Chemistry, University of Richmond, 138 UR Drive, Richmond, Virginia USA 23173, United States
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2
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Sassnink SA, Phan QD, Lam HC, Day AJ, Murray LAM, George JH. Biomimetic synthesis of the non-canonical PPAP natural products yezo'otogirin C and hypermogin D, and studies towards the synthesis of norascyronone A. Org Biomol Chem 2022; 20:1759-1768. [PMID: 35166295 DOI: 10.1039/d2ob00074a] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Oxidative degradation and rearrangement of polycyclic polyprenylated acylphloroglucinols (PPAPs) has created diverse families of unique natural products that are attractive targets for biomimetic synthesis. Herein, we report a racemic synthesis of hyperibrin A and its oxidative radical cyclization to give yezo'otogirin C, followed by epoxidation and House-Meinwald rearrangement to give hypermogin D. We also investigated the biomimetic synthesis of norascyronone A via a similar radical cyclization pathway, with unexpected results that give insight into its biosynthesis.
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Affiliation(s)
- Stefania A Sassnink
- Department of Chemistry, University of Adelaide, Adelaide, SA 5005, Australia.
| | - Quang D Phan
- Department of Chemistry, University of Adelaide, Adelaide, SA 5005, Australia.
| | - Hiu C Lam
- Department of Chemistry, University of Adelaide, Adelaide, SA 5005, Australia.
| | - Aaron J Day
- Department of Chemistry, University of Adelaide, Adelaide, SA 5005, Australia.
| | - Lauren A M Murray
- Department of Chemistry, University of Adelaide, Adelaide, SA 5005, Australia.
| | - Jonathan H George
- Department of Chemistry, University of Adelaide, Adelaide, SA 5005, Australia.
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3
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Tian FX, Qu J. Studies on the Origin of the Stabilizing Effects of Fluorinated Alcohols and Weakly Coordinated Fluorine-Containing Anions on Cationic Reaction Intermediates. J Org Chem 2022; 87:1814-1829. [PMID: 35020378 DOI: 10.1021/acs.joc.1c02361] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Many synthetic methods that use fluorinated alcohols as solvents have been reported, and the fluorinated alcohols have been found to be crucial to the success of these methods. In addition, there have been reports indicating that adding a weakly coordinated fluorine-containing anion, such as BF4-, PF6-, or SbF6-, to fluorinated alcohols can improve yields. The boosting effect of fluorinated alcohols is attributed mainly to hydrogen bond activation. A few studies have suggested that the very polar fluorinated alcohols can stabilize cationic reaction intermediates. However, how they do so and why weakly coordinated fluorine-containing anions improve yields have not been studied in depth. Here, we used quaternary ammonium cations, a quaternary phosphonium cation, and a triaryl-substituted carbocation as models for short-lived cationic intermediates and studied the possible interactions of these cations with fluorinated alcohols and BF4-, PF6-, or SbF6-. On the basis of the results, we propose that the C-F dipoles of fluorinated alcohols and the E-F dipoles (where E is B, P, or Sb) of weakly coordinated fluorine-containing anions stabilized these cations by intermolecular charge-dipole interactions. We deduced that in the same fashion the C-F and E-F dipoles can thermodynamically stabilize cationic reaction intermediates.
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Affiliation(s)
- Feng-Xian Tian
- The State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China
| | - Jin Qu
- The State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China
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Lall MS, Bassyouni A, Bradow J, Brown M, Bundesmann M, Chen J, Ciszewski G, Hagen AE, Hyek D, Jenkinson S, Liu B, Obach RS, Pan S, Reilly U, Sach N, Smaltz DJ, Spracklin DK, Starr J, Wagenaar M, Walker GS. Late-Stage Lead Diversification Coupled with Quantitative Nuclear Magnetic Resonance Spectroscopy to Identify New Structure–Activity Relationship Vectors at Nanomole-Scale Synthesis: Application to Loratadine, a Human Histamine H1 Receptor Inverse Agonist. J Med Chem 2020; 63:7268-7292. [DOI: 10.1021/acs.jmedchem.0c00483] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Manjinder S. Lall
- Pfizer Worldwide Research and Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Asser Bassyouni
- Pfizer Worldwide Research and Development, Science Center Drive, San Diego, California 92121, United States
| | - James Bradow
- Pfizer Worldwide Research and Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Maria Brown
- Pfizer Worldwide Research and Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Mark Bundesmann
- Pfizer Worldwide Research and Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Jinshan Chen
- Pfizer Worldwide Research and Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Gregory Ciszewski
- Pfizer Worldwide Research and Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Anne E. Hagen
- Pfizer Worldwide Research and Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Dennis Hyek
- Spectrix Analytical Services, LLC, 410 Sackett Point Road, Bldg 20, North Haven, Connecticut 06473, United States
| | - Stephen Jenkinson
- Pfizer Worldwide Research and Development, Science Center Drive, San Diego, California 92121, United States
| | - Bo Liu
- Spectrix Analytical Services, LLC, 410 Sackett Point Road, Bldg 20, North Haven, Connecticut 06473, United States
| | - R. Scott Obach
- Pfizer Worldwide Research and Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Senliang Pan
- Pfizer Worldwide Research and Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Usa Reilly
- Pfizer Worldwide Research and Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Neal Sach
- Pfizer Worldwide Research and Development, Science Center Drive, San Diego, California 92121, United States
| | - Daniel J. Smaltz
- Pfizer Worldwide Research and Development, 1 Portland Street, Cambridge, Massachusetts 02139, United States
| | - Douglas K. Spracklin
- Pfizer Worldwide Research and Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Jeremy Starr
- Pfizer Worldwide Research and Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Melissa Wagenaar
- Pfizer Worldwide Research and Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Gregory S. Walker
- Pfizer Worldwide Research and Development, Eastern Point Road, Groton, Connecticut 06340, United States
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5
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Wong THM, Li X, Ma D, Sun J. HNTf 2-Catalyzed Synthesis of Hydrodibenzofurans by an Epoxidation/Semipinacol Rearrangement Cascade. Org Lett 2020; 22:1951-1954. [PMID: 32091907 DOI: 10.1021/acs.orglett.0c00300] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Described here is a highly efficient synthesis of hydrodibenzofurans, an important structural unit lacking general access, in particular, with contiguous quaternary stereocenters. In the presence of HNTf2 as the superior catalyst and mCPBA as an oxidant, the readily available styrene substrates underwent a one-pot cascade process comprising epoxidation, semipinacol rearrangement, and hemiketal formation to furnish hydrodibenzofurans with good efficiency and diastereoselectivity.
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Affiliation(s)
- Ting Hei Matthew Wong
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China
| | - Xingguang Li
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China
| | - Dengke Ma
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China
| | - Jianwei Sun
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China
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Xu C, Xu J. BF3·OEt2-promoted tandem Meinwald rearrangement and nucleophilic substitution of oxiranecarbonitriles. Org Biomol Chem 2020; 18:127-134. [DOI: 10.1039/c9ob02428j] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Introducing a cyano leaving group into epoxides results in BF3·OEt2-promoted tandem Meinwald rearrangement and nucleophilic substitution to synthesize arylacetic derivatives from vicinal arylcyanoepoxides.
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Affiliation(s)
- Chuangchuang Xu
- State Key Laboratory of Chemical Resource Engineering
- Department of Organic Chemistry
- College of Chemistry
- Beijing University of Chemical Technology
- Beijing 100029
| | - Jiaxi Xu
- State Key Laboratory of Chemical Resource Engineering
- Department of Organic Chemistry
- College of Chemistry
- Beijing University of Chemical Technology
- Beijing 100029
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7
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Jiang C, Lu H, Xu WH, Wu J, Yu TY, Xu PF, Wei H. Ni-Catalyzed 1,2-Acyl Migration Reactions Triggered by C–C Bond Activation of Ketones. ACS Catal 2019. [DOI: 10.1021/acscatal.9b04112] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Cheng Jiang
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of the Ministry of Education, College of Chemistry & Materials Science, Northwest University, Xi’an 710069, China
| | - Hong Lu
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of the Ministry of Education, College of Chemistry & Materials Science, Northwest University, Xi’an 710069, China
| | - Wen-Hua Xu
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of the Ministry of Education, College of Chemistry & Materials Science, Northwest University, Xi’an 710069, China
| | - Jianing Wu
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of the Ministry of Education, College of Chemistry & Materials Science, Northwest University, Xi’an 710069, China
| | - Tian-Yang Yu
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of the Ministry of Education, College of Chemistry & Materials Science, Northwest University, Xi’an 710069, China
| | - Peng-Fei Xu
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, China
| | - Hao Wei
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of the Ministry of Education, College of Chemistry & Materials Science, Northwest University, Xi’an 710069, China
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Li S, Shi Y, Li P, Xu J. Nucleophilic Organic Base DABCO-Mediated Chemospecific Meinwald Rearrangement of Terminal Epoxides into Methyl Ketones. J Org Chem 2019; 84:4443-4450. [DOI: 10.1021/acs.joc.8b03171] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Siqi Li
- State Key Laboratory of Chemical Resource Engineering, Department of Organic Chemistry, Faculty of Science, Beijing University of Chemical Technology, Beijing 100029, People’s Republic of China
| | - Yi Shi
- State Key Laboratory of Chemical Resource Engineering, Department of Organic Chemistry, Faculty of Science, Beijing University of Chemical Technology, Beijing 100029, People’s Republic of China
| | - Pingfan Li
- State Key Laboratory of Chemical Resource Engineering, Department of Organic Chemistry, Faculty of Science, Beijing University of Chemical Technology, Beijing 100029, People’s Republic of China
| | - Jiaxi Xu
- State Key Laboratory of Chemical Resource Engineering, Department of Organic Chemistry, Faculty of Science, Beijing University of Chemical Technology, Beijing 100029, People’s Republic of China
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