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Zhuang D, Jiang S, Wang Y, Wang X, Shen S, Yan R. I 2-Mediated [6 + 1] Annulation of Alkynes with MsONH 3OTf: Direct Synthesis of Benzo[ b]azepines. Org Lett 2023; 25:3007-3012. [PMID: 37083284 DOI: 10.1021/acs.orglett.3c00790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/22/2023]
Abstract
The synthesis of benzo[b]azepines using protonated aminating reagent (MsONH3OTf) and alkynes through I2-mediated [6 + 1] annulation reaction has been developed. This protocol features excellent functional group tolerance and mild reaction conditions and affords the benzo[b]azepines in moderate to good yields under metal-free reaction conditions.
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Affiliation(s)
- Daijiao Zhuang
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, 730000 Gansu, China
| | - Shixuan Jiang
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, 730000 Gansu, China
| | - Youzhi Wang
- Chengdu Guibao Science and Technology Co., Ltd, Chengdu, 610041 Sichuan, China
| | - Xiajun Wang
- Chengdu Guibao Science and Technology Co., Ltd, Chengdu, 610041 Sichuan, China
| | - Siwei Shen
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, 730000 Gansu, China
| | - Rulong Yan
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, 730000 Gansu, China
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Saito F. A Sulfoxide Reagent for One-Pot, Three-Component Syntheses of Sulfoxides and Sulfinamides. Angew Chem Int Ed Engl 2022; 61:e202213872. [PMID: 36315415 PMCID: PMC10100148 DOI: 10.1002/anie.202213872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Indexed: 11/27/2022]
Abstract
Sulfoxides and sulfinamides represent versatile sulfur functional groups found in ligands, chiral auxiliaries, and bioactive molecules. Canonical two-component syntheses, however, rely on substrates with a preinstalled C-S bond and impede efficient and modular access to these sulfur motifs. Herein is presented the application of an easily prepared, bench-stable sulfoxide reagent for one-pot, three-component syntheses of sulfoxides and sulfinamides. The sulfoxide reagent donates the SO unit upon the reaction with a Grignard reagent (RMgX) as a sulfenate anion (RSO- ). While subsequent trapping reactions of this key intermediate with carbon electrophiles provide sulfoxides, a range of tertiary, secondary, and primary sulfinamides can be prepared by substitution reactions with electrophilic amines. The syntheses of sulfinamide analogs of amide- and sulfonamide-containing drugs illustrate the utility of the method for the rapid preparation of medicinally relevant molecules.
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Affiliation(s)
- Fumito Saito
- Department Chemie, Ludwig-Maximilians-Universität München, Butenandtstr. 5-13, Haus F, 81377, München, Germany
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Chatterjee S, Harden I, Bistoni G, Castillo RG, Chabbra S, van Gastel M, Schnegg A, Bill E, Birrell JA, Morandi B, Neese F, DeBeer S. A Combined Spectroscopic and Computational Study on the Mechanism of Iron-Catalyzed Aminofunctionalization of Olefins Using Hydroxylamine Derived N-O Reagent as the "Amino" Source and "Oxidant". J Am Chem Soc 2022; 144:2637-2656. [PMID: 35119853 PMCID: PMC8855425 DOI: 10.1021/jacs.1c11083] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
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Herein, we study
the mechanism of iron-catalyzed direct synthesis
of unprotected aminoethers from olefins by a hydroxyl amine derived
reagent using a wide range of analytical and spectroscopic techniques
(Mössbauer, Electron Paramagnetic Resonance, Ultra-Violet Visible
Spectroscopy, X-ray Absorption, Nuclear Resonance Vibrational Spectroscopy,
and resonance Raman) along with high-level quantum chemical calculations.
The hydroxyl amine derived triflic acid salt acts as the “oxidant”
as well as “amino” group donor. It activates the high-spin
Fe(II) (St = 2) catalyst [Fe(acac)2(H2O)2] (1) to generate
a high-spin (St = 5/2) intermediate (Int I), which decays to a second intermediate (Int II) with St = 2. The analysis of spectroscopic
and computational data leads to the formulation of Int I as [Fe(III)(acac)2-N-acyloxy] (an alkyl-peroxo-Fe(III)
analogue). Furthermore, Int II is formed by N–O
bond homolysis. However, it does not generate a high-valent
Fe(IV)(NH) species (a Fe(IV)(O) analogue), but instead a high-spin
Fe(III) center which is strongly antiferromagnetically coupled (J = −524 cm–1) to an iminyl radical,
[Fe(III)(acac)2-NH·], giving St = 2. Though Fe(NH) complexes as isoelectronic surrogates
to Fe(O) functionalities are known, detection of a high-spin Fe(III)-N-acyloxy intermediate (Int I), which undergoes
N–O bond cleavage to generate the active iron–nitrogen
intermediate (Int II), is unprecedented. Relative to
Fe(IV)(O) centers, Int II features a weak elongated Fe–N
bond which, together with the unpaired electron density along the
Fe–N bond vector, helps to rationalize its propensity for N-transfer reactions onto styrenyl olefins, resulting in
the overall formation of aminoethers. This study thus demonstrates
the potential of utilizing the iron-coordinated nitrogen-centered
radicals as powerful reactive intermediates in catalysis.
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Affiliation(s)
- Sayanti Chatterjee
- Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany.,Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
| | - Ingolf Harden
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
| | - Giovanni Bistoni
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
| | - Rebeca G Castillo
- Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Sonia Chabbra
- Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Maurice van Gastel
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
| | - Alexander Schnegg
- Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Eckhard Bill
- Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany
| | - James A Birrell
- Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Bill Morandi
- ETH Zürich, Vladimir-Prelog-Weg 3, HCI, 8093 Zürich, Switzerland.,Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
| | - Frank Neese
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
| | - Serena DeBeer
- Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany
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