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Pandit S, Adhikari AS, Majumdar N. Iridium-Catalyzed Enantioselective Ring Opening of Alkenyl Oxiranes by Unactivated Carboxylic Acids. Org Lett 2022; 24:7388-7393. [PMID: 36197282 DOI: 10.1021/acs.orglett.2c02919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
An iridium-catalyzed enantioselective ring-opening of alkenyl oxiranes by unactivated carboxylic acids has been developed. The reaction undergoes at ambient conditions between an in-situ-generated chiral iridium-π-allyl complex and carboxylic acids to provide rapid access to valuable alkenyl diols in high yields. The synthetic utility of this method is demonstrated by the elaboration of the products into various medium and large ring-sized compounds that are part of biologically relevant molecules.
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Affiliation(s)
- Soumen Pandit
- Medicinal & Process Chemistry Division, CSIR-Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, P.O. Box 173, Lucknow 226031, Uttar Pradesh India
| | - Amit Singh Adhikari
- Medicinal & Process Chemistry Division, CSIR-Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, P.O. Box 173, Lucknow 226031, Uttar Pradesh India
| | - Nilanjana Majumdar
- Medicinal & Process Chemistry Division, CSIR-Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, P.O. Box 173, Lucknow 226031, Uttar Pradesh India
- Academy of Scientific and Innovative Research, New Delhi 110001, India
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2
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Dai C, Zhu J. Predicting dinitrogen activation by borenium and borinium cations. Phys Chem Chem Phys 2022; 24:14651-14657. [PMID: 35670503 DOI: 10.1039/d2cp01233b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The activation of thermodynamically stable and kinetically inert dinitrogen (N2) has been a great challenge due to the significant strength of the triple bond. Recently, in an experimental study on N2 activation by boron species, a highly reactive two-coordinated borylene broke through the limitations of traditional strategies of N2 activation by metal species. Still, studies on metal-free N2 activation remain underdeveloped. Here, we systematically investigate a frustrated Lewis pair (FLP) combining carbene and borenium (or borinium) cations to screen potential candidates for N2 activation via density functional theory calculations. As a result, we found that two FLPs (closed form FLP, borenium and open form FLP, borinium) are able to activate N2 in a thermodynamically and kinetically favorable manner, with a low energy barrier of 9.6 and 7.3 kcal mol-1, respectively. Furthermore, aromaticity was found to play an important role in the stabilization of the products, supported by nucleus-independent chemical shift (NICS), anisotropy of the current-induced density (ACID) and electron density of delocalized bonds (EDDB) analysis. Our findings provide an alternative approach for metal-free N2 activation, highlighting the importance of FLP chemistry and aromaticity in N2 activation.
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Affiliation(s)
- Chenshu Dai
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, P. R. China.
| | - Jun Zhu
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, P. R. China.
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3
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Zhou Y, Chen H, Lei P, Gui C, Wang H, Yan Q, Wang W, Chen F. Palladium-catalyzed base- and solvent-controlled chemoselective allylation of amino acids with allylic carbonates. CHINESE CHEM LETT 2022. [DOI: 10.1016/j.cclet.2022.02.029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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4
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Yang Y, Shang H, Li X, Zhu K, Luan Y. The synthesis of a copper metal‐organic framework Cu
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TDPAT and its application in a Morita‐Baylis‐Hillman (MBH) reaction. Appl Organomet Chem 2022. [DOI: 10.1002/aoc.6566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Yanan Yang
- School of Materials Science and Engineering University of Science and Technology Beijing Beijing China
| | - Hailing Shang
- School of Materials Science and Engineering University of Science and Technology Beijing Beijing China
| | - Xiujuan Li
- School of Materials Science and Engineering University of Science and Technology Beijing Beijing China
| | - Kaicheng Zhu
- Xi'an Key Laboratory of Advanced Photo‐electronics Materials and Energy Conversion Device, School of Sciences Xijing University Xi'an China
| | - Yi Luan
- School of Materials Science and Engineering University of Science and Technology Beijing Beijing China
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5
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Ramirez M, Vece V, Hanessian S, Houk KN. Computational and Further Experimental Explorations of the Competing Cascades Following Claisen Rearrangements of Aryl Propargyl Ethers: Substituent Effects on Reactivity and Regioselectivity. J Org Chem 2021; 86:17955-17964. [PMID: 34846894 DOI: 10.1021/acs.joc.1c02296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We report a computational investigation of two reaction cascades occurring following the Claisen rearrangements of aryl propargyl ethers to the alternate ortho positions in unsymmetrical reactants. Our computations explain how substituents influence reactivity and regioselectivity. Rearrangement to the substituted ortho carbon leads to a tricyclo[3.2.1.0]octane core, while rearrangement to an unsubstituted ortho carbon leads to a benzopyran. Density functional theory with ωB97X-D indicates that these reactions involve rate-determining Claisen rearrangements followed by subsequent reaction cascades of the Claisen rearrangement products depending on the presence or absence of a substituent at the ortho carbon.
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Affiliation(s)
- Melissa Ramirez
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
| | - Vito Vece
- Department of Chemistry, Université de Montréal, P.O. Box 6128, Station Centre-Ville, Montréal, Québec, Canada, H3C3J7
| | - Stephen Hanessian
- Department of Chemistry, Université de Montréal, P.O. Box 6128, Station Centre-Ville, Montréal, Québec, Canada, H3C3J7
| | - K N Houk
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
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Woltornist RA, Collum DB. Ketone Enolization with Sodium Hexamethyldisilazide: Solvent- and Substrate-Dependent E- Z Selectivity and Affiliated Mechanisms. J Am Chem Soc 2021; 143:17452-17464. [PMID: 34643382 PMCID: PMC10042305 DOI: 10.1021/jacs.1c06529] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Ketone enolization by sodium hexamethyldisilazide (NaHMDS) shows a marked solvent and substrate dependence. Enolization of 2-methyl-3-pentanone reveals E-Z selectivities in Et3N/toluene (20:1), methyl-t-butyl ether (MTBE, 10:1), N,N,N',N″,N″-pentamethyldiethylenetriamine (PMDTA)/toluene (8:1), TMEDA/toluene (4:1), diglyme (1:1), DME (1:22), and tetrahydrofuran (THF) (1:90). Control experiments show slow or nonexistent stereochemical equilibration in all solvents except THF. Enolate trapping with Me3SiCl/Et3N requires warming to -40 °C whereas Me3SiOTf reacts within seconds. In situ enolate trapping at -78 °C using preformed NaHMDS/Me3SiCl mixtures is effective in Et3N/toluene yet fails in THF by forming (Me3Si)3N. Rate studies show enolization via mono- and disolvated dimers in Et3N/toluene, disolvated dimers in TMEDA, trisolvated monomers in THF/toluene, and free ions with PMDTA. Density functional theory computations explore the selectivities via the E- and Z-based transition structures. Failures of theory-experiment correlations of ionic fragments were considerable even when isodesmic comparisons could have canceled electron correlation errors. Swapping 2-methyl-3-pentanone with a close isostere, 2-methylcyclohexanone, causes a fundamental change in the mechanism to a trisolvated-monomer-based enolization in THF.
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Affiliation(s)
- Ryan A Woltornist
- 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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Nagamalla S, Dhokale RA, Seidl FJ, Mague JT, Sathyamoorthi S. Unusual Rearrangement-Remercuration Reactions of Allylic Silanols. Org Chem Front 2021; 8:5361-5368. [PMID: 34868598 DOI: 10.1039/d1qo01008e] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
We present the first examples of rearrangement reactions of allylic silanol substrates into linear ketone and 5-membered cyclic silanediol organomercurial products. Both reactions are mediated by Hg(OTf)2 but differ in the use of base, solvent, and temperature. The substrate scope of both transformations was explored, and the product organomercurials were shown to be valuable synthons. Mechanistic studies suggest that both products are the result of a series of transformations, cascading in one pot. DFT analysis provides a basis for understanding the rearrangement of a 6-endo intermediate into the 5-exo cyclic silanediol product.
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Affiliation(s)
- Someshwar Nagamalla
- Department of Medicinal Chemistry, University of Kansas, Lawrence, Kansas, United States, 66047
| | - Ranjeet A Dhokale
- Department of Medicinal Chemistry, University of Kansas, Lawrence, Kansas, United States, 66047
| | | | - Joel T Mague
- Department of Chemistry, Tulane University, New Orleans, Louisiana, United States, 70118
| | - Shyam Sathyamoorthi
- Department of Medicinal Chemistry, University of Kansas, Lawrence, Kansas, United States, 66047
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Williams DR, Gladen PT, Patnaik S. Studies toward norzoanthamine: Ireland–Claisen rearrangements of α,β-unsaturated esters in a stereocontrolled synthesis of trans-fused 2-cyclohexen-1-ones. Tetrahedron 2021. [DOI: 10.1016/j.tet.2021.132354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Dhokale RA, Seidl FJ, Sathyamoorthi S. A Formal Rearrangement of Allylic Silanols. Molecules 2021; 26:molecules26133829. [PMID: 34201779 PMCID: PMC8270268 DOI: 10.3390/molecules26133829] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 06/20/2021] [Accepted: 06/21/2021] [Indexed: 11/23/2022] Open
Abstract
We show that 1M aqueous HCl/THF or NaBH4/DMF allows for demercurative ring-opening of cyclic organomercurial synthons into secondary silanol products bearing terminal alkenes. We had previously demonstrated that primary allylic silanols are readily transformed into cyclic organomercurials using Hg(OTf)2/NaHCO3 in THF. Overall, this amounts to a facile two-step protocol for the rearrangement of primary allylic silanol substrates. Computational investigations suggest that this rearrangement is under thermodynamic control and that the di-tert-butylsilanol protecting group is essential for product selectivity.
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Affiliation(s)
- Ranjeet A. Dhokale
- Department of Medicinal Chemistry, University of Kansas, Lawrence, KS 66047, USA;
| | | | - Shyam Sathyamoorthi
- Department of Medicinal Chemistry, University of Kansas, Lawrence, KS 66047, USA;
- Correspondence:
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