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Pipaón Fernández N, Cruise O, Easton SEF, Kaplan JM, Woodard JL, Hruszkewycz DP, Leitch DC. Direct Heterocycle C-H Alkenylation via Dual Catalysis Using a Palladacycle Precatalyst: Multifactor Optimization and Scope Exploration Enabled by High-Throughput Experimentation. J Org Chem 2024. [PMID: 38206166 DOI: 10.1021/acs.joc.3c02311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2024]
Abstract
One of the major challenges in developing catalytic methods for C-C bond formation is the identification of generally applicable reaction conditions, particularly if multiple substrate structural classes are involved. Pd-catalyzed direct arylation reactions are powerful transformations that enable direct functionalization of C-H bonds; however, the corresponding direct alkenylation reactions, using vinyl (pseudo) halide electrophiles, are less well developed. Inspired by process development efforts toward GSK3368715, an investigational active pharmaceutical ingredient, we report that a Pd(II) palladacycle derived from tri-tert-butylphosphine and Pd(OAc)2 is an effective single-component precatalyst for a variety of direct alkenylation reactions. High-throughput experimentation identified optimal solvent/base combinations for a variety of HetAr-H substrate classes undergoing C-H activation without the need for cocatalysts or stoichiometric silver bases (e.g., Ag2CO3). We propose this reaction proceeds via a dual cooperative catalytic mechanism, where in situ-generated Pd(0) supports a canonical Pd(0)/(II) cross-coupling cycle and the palladacycle effects C-H activation via CMD in a redox-neutral cycle. In all, 192 substrate combinations were tested with a hit rate of approximately 40% and 24 isolated examples. Importantly, this method was applied to prepare a key intermediate in the synthesis of GSK3368715 on multigram scale.
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Affiliation(s)
- Nahiane Pipaón Fernández
- Department of Chemistry, University of Victoria, 3800 Finnerty Road., Victoria, Briish Columbia V8P 5C2, Canada
| | - Odhran Cruise
- Department of Chemistry, University of Victoria, 3800 Finnerty Road., Victoria, Briish Columbia V8P 5C2, Canada
| | - Sarah E F Easton
- Department of Chemistry, University of Victoria, 3800 Finnerty Road., Victoria, Briish Columbia V8P 5C2, Canada
| | - Justin M Kaplan
- Chemical Development, GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426, United States
| | - John L Woodard
- Chemical Development, GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426, United States
| | - Damian P Hruszkewycz
- Chemical Development, GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426, United States
| | - David C Leitch
- Department of Chemistry, University of Victoria, 3800 Finnerty Road., Victoria, Briish Columbia V8P 5C2, Canada
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Spitzer S, Wloka J, Pietruszka J, Kayser O. Generation of Cannabigerolic Acid Derivatives and Their Precursors by Using the Promiscuity of the Aromatic Prenyltransferase NphB. Chembiochem 2023; 24:e202300441. [PMID: 37690998 DOI: 10.1002/cbic.202300441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 09/01/2023] [Accepted: 09/07/2023] [Indexed: 09/12/2023]
Abstract
NphB is an aromatic prenyltransferase with high promiscuity for phenolics including flavonoids, isoflavonoids, and plant polyketides. It has been demonstrated that cannabigerolic acid is successfully formed by the reaction catalysed by NphB using geranyl diphosphate and olivetolic acid as substrates. In this study, the substrate specificity of NphB was further determined by using olivetolic acid derivatives as potential substrates for the formation of new synthetic cannabinoids. The derivatives differ in the hydrocarbon chain attached to C6 of the core structure. We performed in silico experiments, including docking of olivetolic acid derivatives, to identify differences in their binding modes. Substrate acceptance was predicted. Based on these results, a library of olivetolic acid derivatives was constructed and synthesized by using different organic synthetic routes. Conversion was monitored in in vitro assays with purified NphB versions. For the substrates leading to a high conversion olivetolic acid-C8, olivetolic acid-C2 and 2-benzyl-4,6-dihydroxybenzoic acid, the products were further elucidated and identified as cannbigerolic acid derivatives. Therefore, these substrates show potential to be adapted in cannabinoid biosynthesis.
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Affiliation(s)
- Saskia Spitzer
- Technical Biochemistry Laboratory, Technical University Dortmund, 44227, Dortmund, Germany
| | - Jasmin Wloka
- Institute of Bioorganic Chemistry, Heinrich-Heine University Düsseldorf, 52426, Jülich, Germany
| | - Jörg Pietruszka
- Institute of Bioorganic Chemistry, Heinrich-Heine University Düsseldorf, 52426, Jülich, Germany
| | - Oliver Kayser
- Technical Biochemistry Laboratory, Technical University Dortmund, 44227, Dortmund, Germany
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Chen L, Li Y, Bai X, Dong D, Pan M, Huang L, Huang R, Long X, Li Y. Ru(OAc) 3-Catalyzed Regioselective Difunctionalization of Alkynes: Access to ( E)-2-Bromo-1-alkenyl Sulfonates. Org Lett 2023; 25:7025-7029. [PMID: 37708078 DOI: 10.1021/acs.orglett.3c02623] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/16/2023]
Abstract
A new approach is proposed for the divergent and regioselective synthesis of (E)-2-bromo-1-phenylvinyl trifluoromethanesulfonates through alkyne difunctionalization by employing a compatible system of abundantly available alkynes, N-bromosuccinimide (NBS), and trimethylsilyl trifluoromethanesulfonate (TMSOTf) catalyzed by ruthenium(III) acetate [Ru(OAc)3]. It is a novel method for the preparation of vinyl triflate and it offers a fundamental basis for the development of advanced functional compounds, including drugs and organic functional materials. Unlike previously reported methods, the proposed protocol can tolerate a broad range of functional groups. Alkynes derived from bioactive molecules, such as l(-)-borneol, demonstrate the potential value of this new reaction in organic synthesis.
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Affiliation(s)
- Lu Chen
- School of Biotechnology and Health Science, Wuyi University, Jiangmen 529020, China
| | - Ya Li
- School of Biotechnology and Health Science, Wuyi University, Jiangmen 529020, China
| | - Xiaoyan Bai
- School of Biotechnology and Health Science, Wuyi University, Jiangmen 529020, China
| | - Dian Dong
- School of Biotechnology and Health Science, Wuyi University, Jiangmen 529020, China
| | - Meiwei Pan
- School of Biotechnology and Health Science, Wuyi University, Jiangmen 529020, China
| | - Ling Huang
- School of Biotechnology and Health Science, Wuyi University, Jiangmen 529020, China
| | - Runqin Huang
- School of Biotechnology and Health Science, Wuyi University, Jiangmen 529020, China
| | - Xiaotong Long
- School of Biotechnology and Health Science, Wuyi University, Jiangmen 529020, China
| | - Yibiao Li
- School of Biotechnology and Health Science, Wuyi University, Jiangmen 529020, China
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Singla D, Paul K. Ru(II)-Catalyzed Regioselective C(5)-H Functionalization of Quinazolinone-Coumarin Conjugates: Synthesis and Photophysical Studies. J Org Chem 2022; 87:10673-10683. [PMID: 35930499 DOI: 10.1021/acs.joc.2c00872] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The quinazolinone template offers an exciting potential for transforming molecules into useful bioactivity. Herein, we report the first regioselective C-5 alkenylation of quinazolinone-coumarin conjugates via ruthenium(II) catalyst using amide as a weak directing group. This methodology permits excellent regioselectivity, extensive substrate tolerance, and mild reaction conditions. In addition, it generates interesting fluorophores that show positive solvatochromism in the range from 404 nm (toluene) to 541 nm (methanol).
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Affiliation(s)
- Dinesh Singla
- School of Chemistry and Biochemistry, Thapar Institute of Engineering and Technology, Patiala 147001, India
| | - Kamaldeep Paul
- School of Chemistry and Biochemistry, Thapar Institute of Engineering and Technology, Patiala 147001, India
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Belitz F, Seitz AK, Goebel JF, Hu Z, Gooßen LJ. Ru-Catalyzed C-H Arylation of Acrylic Acids with Aryl Bromides. Org Lett 2022; 24:3466-3470. [PMID: 35506600 DOI: 10.1021/acs.orglett.2c01043] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In the presence of a [Ru(p-cymene)Cl2]2/triethylphosphine/lithium carbonate catalyst system, aryl bromides undergo (Z)-selective couplings with unprotected 2-arylacrylic acids to form (Z)-diarylacrylic acids. This vinylic C-H functionalization proceeds in high yields of up to 94% and (Z/E)-ratios of up to 99:1, tolerating a wide range of functional groups. Mechanistic studies indicate that the vinylic C-H activation proceeds via base-assisted cyclometalation rather than via a Heck-type mechanism, which explains its orthogonal stereoselectivity.
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Affiliation(s)
- Florian Belitz
- Department of Chemistry and Biochemistry, Ruhr-Universität Bochum, NC 2/170, Universitätsstrasse 150, 44801 Bochum, Germany
| | - Ann-Katrin Seitz
- Department of Chemistry and Biochemistry, Ruhr-Universität Bochum, NC 2/170, Universitätsstrasse 150, 44801 Bochum, Germany
| | - Jonas F Goebel
- Department of Chemistry and Biochemistry, Ruhr-Universität Bochum, NC 2/170, Universitätsstrasse 150, 44801 Bochum, Germany
| | - Zhiyong Hu
- Department of Chemistry and Biochemistry, Ruhr-Universität Bochum, NC 2/170, Universitätsstrasse 150, 44801 Bochum, Germany
| | - Lukas J Gooßen
- Department of Chemistry and Biochemistry, Ruhr-Universität Bochum, NC 2/170, Universitätsstrasse 150, 44801 Bochum, Germany
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