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Anderson DE, Tortajada A, Hevia E. New Frontiers in Organosodium Chemistry as Sustainable Alternatives to Organolithium Reagents. Angew Chem Int Ed Engl 2024; 63:e202313556. [PMID: 37801443 DOI: 10.1002/anie.202313556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 10/05/2023] [Accepted: 10/06/2023] [Indexed: 10/08/2023]
Abstract
With their highly reactive respective C-Na and N-Na bonds, organosodium and sodium amide reagents could be viewed as obvious replacements or even superior reagents to the popular, widely utilised organolithiums. However, they have seen very limited applications in synthesis due mainly to poor solubility in common solvents and their limited stability. That notwithstanding in recent years there has been a surge of interest in bringing these sustainable metal reagents into the forefront of organometallics in synthesis. Showcasing the growth in utilisation of organosodium complexes within several areas of synthetic chemistry, this Minireview discusses promising new methods that have been recently reported with the goal of taming these powerful reagents. Special emphasis is placed on coordination and aggregation effects in these reagents which can impart profound changes in their solubility and reactivity. Differences in observed reactivity between more nucleophilic aryl and alkyl sodium reagents and the less nucleophilic but highly basic sodium amides are discussed along with current mechanistic understanding of their reactivities. Overall, this review aims to inspire growth in this exciting field of research to allow for the integration of organosodium complexes within common important synthetic transformations.
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Affiliation(s)
- David E Anderson
- Department für Chemie und Biochemie, Universität Bern, Freiestrasse 3, 3012, Bern, Switzerland
| | - Andreu Tortajada
- Department für Chemie und Biochemie, Universität Bern, Freiestrasse 3, 3012, Bern, Switzerland
| | - Eva Hevia
- Department für Chemie und Biochemie, Universität Bern, Freiestrasse 3, 3012, Bern, Switzerland
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2
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Yang S, Hu H, Chen M. Photoinduced Palladium-Catalyzed Regio- and Chemoselective Elimination of Primary Alkyl Bromides: A Mild Route to Synthesize Unactivated Terminal Olefins. Org Lett 2023; 25:7968-7973. [PMID: 37888796 DOI: 10.1021/acs.orglett.3c02980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2023]
Abstract
Presented is a highly efficient method for visible-light-induced regio- and chemoselective elimination of alkyl halides yielding unactivated terminal olefins vital in organic synthesis. Achieved through ligand control, the reaction exhibits remarkable regioselectivity and suppresses undesired side reactions, particularly 1,5-hydrogen atom transfer (HAT). The process favors primary alkyl halides while preserving secondary and tertiary alkyl bromides, thereby enabling the incorporation of terminal olefins in complex molecules for late-stage functionalization.
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Affiliation(s)
- Sen Yang
- Jiangsu Key Laboratory of Advanced Catalytic Materials & Technology, School of Petrochemical Engineering, Changzhou University, Changzhou 213164, China
| | - Hao Hu
- Jiangsu Key Laboratory of Advanced Catalytic Materials & Technology, School of Petrochemical Engineering, Changzhou University, Changzhou 213164, China
| | - Ming Chen
- Jiangsu Key Laboratory of Advanced Catalytic Materials & Technology, School of Petrochemical Engineering, Changzhou University, Changzhou 213164, China
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Harenberg JH, Reddy Annapureddy R, Karaghiosoff K, Knochel P. Continuous Flow Preparation of Benzylic Sodium Organometallics. Angew Chem Int Ed Engl 2022; 61:e202203807. [PMID: 35416397 PMCID: PMC9400861 DOI: 10.1002/anie.202203807] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Indexed: 12/14/2022]
Abstract
We report a lateral sodiation of alkyl(hetero)arenes using on-demand generated hexane-soluble (2-ethylhexyl)sodium (1) in the presence of TMEDA. (2-Ethylhexyl)sodium (1) is prepared via a sodium packed-bed reactor and used for metalations at ambient temperature in batch as well as in continuous flow. The resulting benzylic sodium species are subsequently trapped with various electrophiles including carbonyl compounds, epoxides, oxetane, allyl/benzyl chlorides, alkyl halides and alkyl tosylates. Wurtz-type couplings with secondary alkyl halides and tosylates proceed under complete inversion of stereochemistry. Furthermore, the utility of this lateral sodiation is demonstrated in the synthesis of pharmaceutical relevant compounds. Thus, fingolimod is prepared from p-xylene applying the lateral sodiation twice. In addition, 7-fold isotopically labeled salmeterol-d7 and fenpiprane as well as precursors to super linear alkylbenzene (SLAB) surfactants are prepared.
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Affiliation(s)
- Johannes H. Harenberg
- Department ChemieLudwig-Maximilians-Universität MünchenButenandtstraße 5–13, Haus F81377MünchenGermany
| | | | - Konstantin Karaghiosoff
- Department ChemieLudwig-Maximilians-Universität MünchenButenandtstraße 5–13, Haus F81377MünchenGermany
| | - Paul Knochel
- Department ChemieLudwig-Maximilians-Universität MünchenButenandtstraße 5–13, Haus F81377MünchenGermany
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Harenberg JH, Annapureddy RR, Karaghiosoff K, Knochel P. Continuous Flow Preparation of Benzylic Sodium Organometallics. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202203807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
| | | | | | - Paul Knochel
- Ludwig-Maximilians-Universitat Munchen Department of Chemistry Butenandtstr. 5-13 81377 München GERMANY
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Ma Y, Woltornist RA, Algera RF, Collum DB. Reactions of Sodium Diisopropylamide: Liquid-Phase and Solid-Liquid Phase-Transfer Catalysis by N, N, N', N″, N″-Pentamethyldiethylenetriamine. J Am Chem Soc 2021; 143:13370-13381. [PMID: 34375095 PMCID: PMC10042303 DOI: 10.1021/jacs.1c06528] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Sodium diisopropylamide (NaDA) in N,N-dimethylethylamine (DMEA) and DMEA-hydrocarbon mixtures with added N,N,N',N″,N″-pentamethyldiethylenetriamine (PMDTA) reacts with alkyl halides, epoxides, hydrazones, arenes, alkenes, and allyl ethers. Comparisons of PMDTA with N,N,N',N'-tetramethylethylenediamine (TMEDA) accompanied by detailed rate and computational studies reveal the importance of the trifunctionality and κ2-κ3 hemilability. Rate studies show exclusively monomer-based reactions of 2-bromooctane, cyclooctene oxide, and dimethylresorcinol. Catalysis with 10 mol % PMDTA shows up to >30-fold accelerations (kcat > 300) with no evidence of inhibition over 10 turnovers. Solid-liquid phase-transfer catalysis (SLPTC) is explored as a means to optimize the catalysis as well as explore the merits of heterogeneous reaction conditions.
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Affiliation(s)
- Yun Ma
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853–1301
| | - Ryan A. Woltornist
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853–1301
| | - Russell F. Algera
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853–1301
| | - David B. Collum
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853–1301
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Harenberg JH, Weidmann N, Wiegand AJ, Hoefer CA, Annapureddy RR, Knochel P. (2-Ethylhexyl)sodium: A Hexane-Soluble Reagent for Br/Na-Exchanges and Directed Metalations in Continuous Flow. Angew Chem Int Ed Engl 2021; 60:14296-14301. [PMID: 33826212 PMCID: PMC8252725 DOI: 10.1002/anie.202103031] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Indexed: 12/14/2022]
Abstract
We report the on-demand generation of hexane-soluble (2-ethylhexyl)sodium (1) from 3-(chloromethyl)heptane (2) using a sodium-packed-bed reactor under continuous flow conditions. Thus, the resulting solution of 1 is free of elemental sodium and therefore suited for a range of synthetic applications. This new procedure avoids the storage of an alkylsodium and limits the handling of metallic sodium to a minimum. (2-Ethylhexyl)sodium (1) proved to be a very useful reagent and undergoes in-line Br/Na-exchanges as well as directed sodiations. The resulting arylsodium intermediates are subsequently trapped in batch with various electrophiles such as ketones, aldehydes, Weinreb-amides, imines, allyl bromides, disulfides and alkyl iodides. A reaction scale-up of the Br/Na-exchange using an in-line electrophile quench was also reported.
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Affiliation(s)
- Johannes H. Harenberg
- Department ChemieLudwig-Maximilians-Universität MünchenButenandtstrasse 5–13, Haus F81377MünchenGermany
| | - Niels Weidmann
- Department ChemieLudwig-Maximilians-Universität MünchenButenandtstrasse 5–13, Haus F81377MünchenGermany
| | - Alexander J. Wiegand
- Department ChemieLudwig-Maximilians-Universität MünchenButenandtstrasse 5–13, Haus F81377MünchenGermany
| | - Carla A. Hoefer
- Department ChemieLudwig-Maximilians-Universität MünchenButenandtstrasse 5–13, Haus F81377MünchenGermany
| | | | - Paul Knochel
- Department ChemieLudwig-Maximilians-Universität MünchenButenandtstrasse 5–13, Haus F81377MünchenGermany
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Harenberg JH, Weidmann N, Wiegand AJ, Hoefer CA, Annapureddy RR, Knochel P. (2‐Ethylhexyl)natrium: Ein hexanlösliches Reagenz für Br/Na‐Austauschreaktionen und dirigierte Metallierungen im kontinuierlichen Durchfluss. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202103031] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Johannes H. Harenberg
- Department Chemie Ludwig-Maximilians-Universität München Butenandtstrasse 5–13, Haus F 81377 München Deutschland
| | - Niels Weidmann
- Department Chemie Ludwig-Maximilians-Universität München Butenandtstrasse 5–13, Haus F 81377 München Deutschland
| | - Alexander J. Wiegand
- Department Chemie Ludwig-Maximilians-Universität München Butenandtstrasse 5–13, Haus F 81377 München Deutschland
| | - Carla A. Hoefer
- Department Chemie Ludwig-Maximilians-Universität München Butenandtstrasse 5–13, Haus F 81377 München Deutschland
| | - Rajasekar Reddy Annapureddy
- Department Chemie Ludwig-Maximilians-Universität München Butenandtstrasse 5–13, Haus F 81377 München Deutschland
| | - Paul Knochel
- Department Chemie Ludwig-Maximilians-Universität München Butenandtstrasse 5–13, Haus F 81377 München Deutschland
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Gentner TX, Mulvey RE. Alkali-Metal Mediation: Diversity of Applications in Main-Group Organometallic Chemistry. Angew Chem Int Ed Engl 2021; 60:9247-9262. [PMID: 33017511 PMCID: PMC8247348 DOI: 10.1002/anie.202010963] [Citation(s) in RCA: 95] [Impact Index Per Article: 31.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Indexed: 12/23/2022]
Abstract
Organolithium compounds have been at the forefront of synthetic chemistry for over a century, as they mediate the synthesis of myriads of compounds that are utilised worldwide in academic and industrial settings. For that reason, lithium has always been the most important alkali metal in organometallic chemistry. Today, that importance is being seriously challenged by sodium and potassium, as the alkali-metal mediation of organic reactions in general has started branching off in several new directions. Recent examples covering main-group homogeneous catalysis, stoichiometric organic synthesis, low-valent main-group metal chemistry, polymerization, and green chemistry are showcased in this Review. Since alkali-metal compounds are often not the end products of these applications, their roles are rarely given top billing. Thus, this Review has been written to alert the community to this rising unifying phenomenon of "alkali-metal mediation".
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Affiliation(s)
- Thomas X. Gentner
- Department of Pure and Applied ChemistryUniversity of StrathclydeGlasgowG1 1XLUK
| | - Robert E. Mulvey
- Department of Pure and Applied ChemistryUniversity of StrathclydeGlasgowG1 1XLUK
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Gentner TX, Mulvey RE. Alkalimetall‐Mediatoren: Vielfältige Anwendungen in der metallorganischen Chemie der Hauptgruppenelemente. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202010963] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Thomas X. Gentner
- Department of Pure and Applied Chemistry University of Strathclyde Glasgow G1 1XL Großbritannien
| | - Robert E. Mulvey
- Department of Pure and Applied Chemistry University of Strathclyde Glasgow G1 1XL Großbritannien
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Woltornist RA, Ma Y, Algera RF, Zhou Y, Zhang Z, Collum DB. Structure, Reactivity, and Synthetic Applications of Sodium Diisopropylamide. SYNTHESIS-STUTTGART 2020; 52:1478-1497. [PMID: 34349297 PMCID: PMC8330442 DOI: 10.1055/s-0039-1690846] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The 60-year history of sodium diisopropylamide (NaDA) is described herein. We review various preparations, solvent-dependent stabilities, and solution structures. Synthetic applications of NaDA reported to date are framed by a mechanism-driven approach, emphasizing selectivities when appropriate. We conclude with examples beyond metalation in which NaDA plays a central role and a few thoughts on where future applications could be focused.
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Affiliation(s)
- Ryan A. Woltornist
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853–1301
| | - Yun Ma
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853–1301
| | - Russell F. Algera
- Pfizer Worldwide Research and Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Yuhui Zhou
- Frontage Laboratories, Inc., 75 E Uwchlan Avenue, Suite 100, Exton, PA, 19341
| | - Zirong Zhang
- Department of Chemistry, University of Michigan, CHEM 3614 930 North University Ave, Ann Arbor, MI, 48109
| | - David B. Collum
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853–1301
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Zhou Y, Keresztes I, MacMillan SN, Collum DB. Disodium Salts of Pseudoephedrine-Derived Myers Enolates: Stereoselectivity and Mechanism of Alkylation. J Am Chem Soc 2019; 141:16865-16876. [PMID: 31613094 DOI: 10.1021/jacs.9b08176] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Pseudoephedrine-derived dianionic Myers enolates were generated using sodium diisopropylamide (NaDA) in THF solution. The reactivities and selectivities of the disodium salts largely mirror those of the dilithium salts but without the requisite large excesses of inorganic salts (LiCl) or mandated dilute solutions. The disodium salts require careful control of temperature to preclude deleterious aggregate aging effects traced to changes in the aggregate structure and intervening O-alkylations. Structural studies and density functional theory (DFT) computations show a dominant highly symmetric polyhedron quite different from the lithium analogue. No enolate-NaDA mixed aggregates are observed with excess NaDA. Rate studies show an alkylation mechanism involving an intervening tetramer-monomer pre-equilibrium followed by rate-limiting alkylation of tetrasolvated monomers. DFT computations were conducted to explore the possible influences on stereochemistry. A crystal deriving from samples aged at ambient temperature contains six dianionic subunits and two monoanionic (alkoxide-only) subunits. A new preparation of concentrated solutions of NaDA in THF solution is described.
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Affiliation(s)
- Yuhui Zhou
- Department of Chemistry and Chemical Biology, Baker Laboratory , Cornell University , Ithaca , New York 14853-1301 , United States
| | - Ivan Keresztes
- Department of Chemistry and Chemical Biology, Baker Laboratory , Cornell University , Ithaca , New York 14853-1301 , United States
| | - Samantha N MacMillan
- Department of Chemistry and Chemical Biology, Baker Laboratory , Cornell University , Ithaca , New York 14853-1301 , United States
| | - David B Collum
- Department of Chemistry and Chemical Biology, Baker Laboratory , Cornell University , Ithaca , New York 14853-1301 , United States
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Ma Y, Woltornist RA, Algera RF, Collum DB. Aryl Carbamates: Mechanisms of Orthosodiations and Snieckus-Fries Rearrangements. J Org Chem 2019; 84:9051-9057. [PMID: 31257864 DOI: 10.1021/acs.joc.9b00968] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Aryl carbamates are orthometalated by sodium diisopropylamide (NaDA) in tetrahydrofuran. The resulting arylsodiums undergo Snieckus-Fries rearrangement to give orthoacylated phenols in good yield. The intermediate arylsodiums and resulting orthoacylated phenolates are suggested to be monomeric. The rate-limiting step in the two-step sequence depends on the steric demands of the carbamoyl moiety and the substituents in the meta position of the arene. Rate studies reveal a dominant disolvated-monomer-based orthometalation followed by a di- or trisolvated arylsodium monomer-based rearrangement. Kinetic evidence of a NaDA-catalyzed Snieckus-Fries rearrangement suggests the intermediacy of mixed trimers. Competitive halide eliminations to form benzyne are also discussed.
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Affiliation(s)
- Yun Ma
- Department of Chemistry and Chemical Biology Baker Laboratory , Cornell University , Ithaca , New York 14853-1301 , United States
| | - Ryan A Woltornist
- Department of Chemistry and Chemical Biology Baker Laboratory , Cornell University , Ithaca , New York 14853-1301 , United States
| | - Russell F Algera
- Department of Chemistry and Chemical Biology Baker Laboratory , Cornell University , Ithaca , New York 14853-1301 , United States
| | - David B Collum
- Department of Chemistry and Chemical Biology Baker Laboratory , Cornell University , Ithaca , New York 14853-1301 , United States
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