1
|
Mueller LG, Keller TM, Fleming FF. One-Pot Syntheses of Substituted Oxazoles and Imidazoles from the Isocyanide Asmic. J Org Chem 2023; 88:909-916. [PMID: 36598123 DOI: 10.1021/acs.joc.2c02290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Substituted oxazoles and imidazoles are synthesized in one pot from the isocyanide building block Asmic (anisylsulfanylmethyl isocyanide), an alkyl halide, and an acid chloride or nitrile, respectively. The modular assembly employs sequential deprotonation-alkylation and deprotonation-acylation or imination of Asmic, followed by an unusual carbon-sulfur bond cleavage to construct the azole. The strategy is robust, highly efficient, and affords C4-C5 disubstituted oxazoles or imidazoles in a single operation.
Collapse
Affiliation(s)
- Louis G Mueller
- Johns Hopkins Drug Discovery, Baltimore, Maryland 21205, United States
| | - Taylor M Keller
- Department of Chemistry, University of Pennsylvania, 231 S. 34 Street, Philadelphia, Pennsylvania 19104, United States
| | - Fraser F Fleming
- Department of Chemistry, Drexel University, 3401 Chestnut Street, Philadelphia, Pennsylvania 19104, United States
| |
Collapse
|
2
|
Mueller LG, Chao A, Alwedi E, Natrajan M, Fleming FF. Oxazole Synthesis by Sequential Asmic-Ester Condensations and Sulfanyl-Lithium Exchange-Trapping. Org Lett 2021; 23:1500-1503. [PMID: 33533625 DOI: 10.1021/acs.orglett.1c00288] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Oxazoles are rapidly assembled through a sequential deprotonation-condensation of Asmic, anisylsulfanylmethylisocyanide, with esters followed by sulfanyl-lithium exchange-trapping. Deprotonating Asmic affords a metalated isocyanide that efficiently traps esters to afford oxazoles bearing a versatile C-4 anisylsulfanyl substituent. Interchange of the anisylsulfanyl substituent is readily achieved through a first-in-class sulfur-lithium exchange-electrophilic trapping sequence whose versatility is illustrated in the three-step synthesis of the bioactive natural product streptochlorin.
Collapse
Affiliation(s)
- Louis G Mueller
- Department of Chemistry, Drexel University, 32 South 32nd Street Philadelphia, Pennsylvania 19104, United States
| | - Allen Chao
- Wistar Institute, 3601 Spruce Street, Philadelphia, Pennsylvania 19104, United States
| | - Embarek Alwedi
- Merck Inc., 90 East Scott Avenue, Rahway, New Jersey 07065, United States
| | - Maanasa Natrajan
- Department of Chemistry, Drexel University, 32 South 32nd Street Philadelphia, Pennsylvania 19104, United States
| | - Fraser F Fleming
- Department of Chemistry, Drexel University, 32 South 32nd Street Philadelphia, Pennsylvania 19104, United States
| |
Collapse
|
3
|
Alazet S, West MS, Patel P, Rousseaux SAL. Synthesis of Nitrile‐Bearing Quaternary Centers by an Equilibrium‐Driven Transnitrilation and Anion‐Relay Strategy. Angew Chem Int Ed Engl 2019; 58:10300-10304. [DOI: 10.1002/anie.201903215] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 05/07/2019] [Indexed: 11/12/2022]
Affiliation(s)
- Sébastien Alazet
- Davenport Research LaboratoriesDepartment of ChemistryUniversity of Toronto 80 St George Street Toronto Ontario M5S 3H6 Canada
| | - Michael S. West
- Davenport Research LaboratoriesDepartment of ChemistryUniversity of Toronto 80 St George Street Toronto Ontario M5S 3H6 Canada
| | - Purvish Patel
- Davenport Research LaboratoriesDepartment of ChemistryUniversity of Toronto 80 St George Street Toronto Ontario M5S 3H6 Canada
| | - Sophie A. L. Rousseaux
- Davenport Research LaboratoriesDepartment of ChemistryUniversity of Toronto 80 St George Street Toronto Ontario M5S 3H6 Canada
| |
Collapse
|
4
|
Alazet S, West MS, Patel P, Rousseaux SAL. Synthesis of Nitrile‐Bearing Quaternary Centers by an Equilibrium‐Driven Transnitrilation and Anion‐Relay Strategy. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201903215] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Sébastien Alazet
- Davenport Research LaboratoriesDepartment of ChemistryUniversity of Toronto 80 St George Street Toronto Ontario M5S 3H6 Canada
| | - Michael S. West
- Davenport Research LaboratoriesDepartment of ChemistryUniversity of Toronto 80 St George Street Toronto Ontario M5S 3H6 Canada
| | - Purvish Patel
- Davenport Research LaboratoriesDepartment of ChemistryUniversity of Toronto 80 St George Street Toronto Ontario M5S 3H6 Canada
| | - Sophie A. L. Rousseaux
- Davenport Research LaboratoriesDepartment of ChemistryUniversity of Toronto 80 St George Street Toronto Ontario M5S 3H6 Canada
| |
Collapse
|
5
|
Hintz H, Vanas A, Klose D, Jeschke G, Godt A. Trityl Radicals with a Combination of the Orthogonal Functional Groups Ethyne and Carboxyl: Synthesis without a Statistical Step and EPR Characterization. J Org Chem 2019; 84:3304-3320. [DOI: 10.1021/acs.joc.8b03234] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Henrik Hintz
- Faculty of Chemistry and Center for Molecular Materials (CM2), Bielefeld University, Universitätsstrasse 25, 33615 Bielefeld, Germany
| | - Agathe Vanas
- Laboratory of Physical Chemistry, ETH Zurich, Vladimir-Prelog-Weg 2, 8093 Zurich, Switzerland
| | - Daniel Klose
- Laboratory of Physical Chemistry, ETH Zurich, Vladimir-Prelog-Weg 2, 8093 Zurich, Switzerland
| | - Gunnar Jeschke
- Laboratory of Physical Chemistry, ETH Zurich, Vladimir-Prelog-Weg 2, 8093 Zurich, Switzerland
| | - Adelheid Godt
- Faculty of Chemistry and Center for Molecular Materials (CM2), Bielefeld University, Universitätsstrasse 25, 33615 Bielefeld, Germany
| |
Collapse
|
6
|
Alwedi E, Lujan-Montelongo JA, Pitta BR, Chao A, Cortés-Mejía R, Del Campo JM, Fleming FF. Asmic: An Exceptional Building Block for Isocyanide Alkylations. Org Lett 2018; 20:5910-5913. [PMID: 30188137 DOI: 10.1021/acs.orglett.8b02574] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Asmic addresses the long-standing challenge of alkylating isocyanides, providing access to isocyanides with diverse substitution patterns. The o-anisylsulfanyl group serves a critical dual role by facilitating deprotonation-alkylation and providing a latent nucleophilic site through an unusual arylsulfanyl-lithium exchange.
Collapse
Affiliation(s)
- Embarek Alwedi
- Department of Chemistry , Drexel University , 32 South 32nd Street , Philadelphia , Pennsylvania 19104 , United States
| | - J Armando Lujan-Montelongo
- Department of Chemistry , Drexel University , 32 South 32nd Street , Philadelphia , Pennsylvania 19104 , United States
| | - Bhaskar R Pitta
- Department of Chemistry , Drexel University , 32 South 32nd Street , Philadelphia , Pennsylvania 19104 , United States
| | - Allen Chao
- Department of Chemistry , Drexel University , 32 South 32nd Street , Philadelphia , Pennsylvania 19104 , United States
| | - Rodrigo Cortés-Mejía
- Department of Chemistry , Drexel University , 32 South 32nd Street , Philadelphia , Pennsylvania 19104 , United States
| | - Jorge M Del Campo
- Department of Chemistry , Drexel University , 32 South 32nd Street , Philadelphia , Pennsylvania 19104 , United States
| | - Fraser F Fleming
- Department of Chemistry , Drexel University , 32 South 32nd Street , Philadelphia , Pennsylvania 19104 , United States
| |
Collapse
|
7
|
Yang X, Fleming FF. C- and N-Metalated Nitriles: The Relationship between Structure and Selectivity. Acc Chem Res 2017; 50:2556-2568. [PMID: 28930437 DOI: 10.1021/acs.accounts.7b00329] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Metalated nitriles are exceptional nucleophiles capable of forging highly hindered stereocenters in cases where enolates are unreactive. The excellent nucleophilicity emanates from the powerful inductive stabilization of adjacent negative charge by the nitrile, which has a miniscule steric demand. Inductive stabilization is the key to understanding the reactivity of metalated nitriles because this permits a continuum of structures that range from N-metalated ketenimines to nitrile anions. Solution and solid-state analyses reveal two different metal coordination sites, the formally anionic carbon and the nitrile nitrogen, with the site of metalation depending intimately on the solvent, counterion, temperature, and ligands. The most commonly encountered structures, C- and N-metalated nitriles, have either sp3 or sp2 hybridization at the nucleophilic carbon, which essentially translates into two distinct organometallic species with similar but nonidentical stereoselectivity, regioselectivity, and reactivity preferences. The hybridization differences are particularly important in SNi displacements of cyclic nitriles because the orbital orientations create very precise trajectories that control the cyclization selectivity. Harnessing the orbital differences between C- and N-metalated nitriles allows selective cyclization to afford nitrile-containing cis- or trans-hydrindanes, decalins, or bicyclo[5.4.0]undecanes. Similar orbital constraints favor preferential SNi displacements with allylic electrophiles on sp3 centers over sp2 centers. The strategy permits stereoselective displacements on secondary centers to set contiguous tertiary and quaternary stereocenters or even contiguous vicinal quaternary centers. Stereoselective alkylations of acyclic nitriles are inherently more challenging because of the difficulty in creating steric differentiation in a dynamic system with rotatable bonds. However, judicious substituent placement of vicinal dimethyl groups and a trisubstituted alkene sufficiently constrains C- and N-metalated nitriles to install quaternary stereocenters with excellent 1,2-induction. The structural differences between C- and N-metalated nitriles permit a rare series of chemoselective alkylations with bifunctional electrophiles. C-Magnesiated nitriles preferentially react with carbonyl electrophiles, whereas N-lithiated nitriles favor SN2 displacement of alkyl halides. The chemoselective alkylations potentially provide a strategy for late-stage alkylations of polyfunctional electrophiles en route to bioactive targets. In this Account, the bonding of metalated nitriles is summarized as a prelude to the different strategies for selectively preparing C- and N-metalated nitriles. With this background, the Account then transitions to applications in which C- or N-metalated nitriles allow complementary diastereoselectivity in alkylations and arylations, and regioselective alkylations and arylations, with acyclic and cyclic nitriles. In the latter sections, a series of regiodivergent cyclizations are described that provide access to cis- and trans-hydrindanes and decalins, structural motifs embedded within a plethora of natural products. The last section describes chemoselective alkylations and acylations of C- and N-metalated nitriles that offer the tantalizing possibility of selectively manipulating functional groups in bioactive medicinal leads without recourse to protecting groups. Collectively, the unusual reactivity profiles of C- and N-metalated nitriles provide new strategies for rapidly and selectively accessing valuable synthetic precursors.
Collapse
Affiliation(s)
- Xun Yang
- Department of Chemistry, Drexel University, Philadelphia, Pennsylvania 19104, United States
| | - Fraser F. Fleming
- Department of Chemistry, Drexel University, Philadelphia, Pennsylvania 19104, United States
| |
Collapse
|
8
|
Yang X, Nath D, Gau MR, Steward OW, Fleming FF. Sulfone–Metal Exchange and Alkylation of Sulfonylnitriles. Angew Chem Int Ed Engl 2017; 56:7257-7260. [DOI: 10.1002/anie.201704028] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Indexed: 11/11/2022]
Affiliation(s)
- Xun Yang
- Department of Chemistry Drexel University 32 South 32nd St. Philadelphia PA 19104 USA
| | - Dinesh Nath
- Department of Chemistry University of Oklahoma Norman OK 73019 USA
| | - Michael R. Gau
- Department of Chemistry Temple University 420 Beury Hall, 1901 N. 13th St. Philadelphia PA 19122 USA
| | - Omar W. Steward
- Department of Chemistry Duquesne University Pittsburgh PA 15282 USA
| | - Fraser F. Fleming
- Department of Chemistry Drexel University 32 South 32nd St. Philadelphia PA 19104 USA
| |
Collapse
|
9
|
|
10
|
Sadhukhan A, Hobbs MC, Meijer AJHM, Coldham I. Highly enantioselective metallation-substitution alpha to a chiral nitrile. Chem Sci 2017; 8:1436-1441. [PMID: 28616143 PMCID: PMC5460602 DOI: 10.1039/c6sc03712g] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Accepted: 10/24/2016] [Indexed: 11/21/2022] Open
Abstract
Nitrile anions do not necessarily lack stereochemical integrity and we show good results for stereospecific reaction with a simple magnesium base.
We report the deprotonation of a chiral nitrile and reaction of the resulting chiral organometallic species with a variety of electrophiles to give highly enantiomerically enriched 2-substituted nitrile products. The nitrile was treated with TMPMgCl and the resulting anion, an asymmetric alpha cyano Grignard species, was found to be configurationally stable at low temperature for a short time (half-life several minutes at –104 °C).
Collapse
Affiliation(s)
- Arghya Sadhukhan
- Department of Chemistry , University of Sheffield , Brook Hill , Sheffield , S3 7HF , UK .
| | - Melanie C Hobbs
- Department of Chemistry , University of Sheffield , Brook Hill , Sheffield , S3 7HF , UK .
| | - Anthony J H M Meijer
- Department of Chemistry , University of Sheffield , Brook Hill , Sheffield , S3 7HF , UK .
| | - Iain Coldham
- Department of Chemistry , University of Sheffield , Brook Hill , Sheffield , S3 7HF , UK .
| |
Collapse
|
11
|
Yang X, Nath D, Morse J, Ogle C, Yurtoglu E, Altundas R, Fleming F. Cyclic Alkenenitriles: Copper-Catalyzed Deconjugative α-Alkylation. J Org Chem 2016; 81:4098-102. [DOI: 10.1021/acs.joc.6b00367] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Xun Yang
- Department
of Chemistry, Duquesne University, Pittsburgh, Pennsylvania 15282, United States
| | - Dinesh Nath
- Department
of Chemistry, University of Oklahoma, Norman, Oklahoma 73019, United States
| | - Jared Morse
- Department
of Chemistry, The University of North Carolina at Charlotte, Charlotte, North Carolina 28223, United States
| | - Craig Ogle
- Department
of Chemistry, The University of North Carolina at Charlotte, Charlotte, North Carolina 28223, United States
| | - Emine Yurtoglu
- Department
of Chemistry, Ataturk University, 25240 Erzurum, Turkey
| | - Ramazan Altundas
- Department
of Chemistry, Ataturk University, 25240 Erzurum, Turkey
| | - Fraser Fleming
- Department
of Chemistry, Drexel University, Philadelphia, Pennsylvania 19104, United States
| |
Collapse
|
12
|
Lu P, Pakkala VS, Evanseck JD, Fleming FF. Metalated nitriles: S Ni' cyclizations with a propargylic electrophile. Tetrahedron Lett 2015; 56:3216-3219. [PMID: 26120212 PMCID: PMC4480775 DOI: 10.1016/j.tetlet.2015.01.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
A rare 5-exo-dig SNi' cyclization with magnesiated and lithiated nitriles affords a cis-fused hydrindane bearing an exocyclic allene. The cyclization of the dilithiated nitrile pits a stereoelectronic preference for a trans-hydrindane against a cyclization through a less strained transition structure to the corresponding cis-hydrindane. Computational modeling suggests that the dilithiated nitrile cyclizes to a cis-hydrindane because the preferred transition structure positions the lithium cation in a cone of electron density that bridges the nitrile-bearing carbon, an alkoxide, and an electron-rich alkyne functionality.
Collapse
Affiliation(s)
- Ping Lu
- Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, PA 15282-1530, USA
| | - Venkata S. Pakkala
- Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, PA 15282-1530, USA
| | - Jeffrey D. Evanseck
- Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, PA 15282-1530, USA
| | - Fraser F. Fleming
- Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, PA 15282-1530, USA
| |
Collapse
|
13
|
Kondo M, Kobayashi N, Hatanaka T, Funahashi Y, Nakamura S. Catalytic Enantioselective Reaction of α-Phenylthioacetonitriles with Imines Using Chiral Bis(imidazoline)-Palladium Catalysts. Chemistry 2015; 21:9066-70. [DOI: 10.1002/chem.201501351] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Indexed: 11/11/2022]
|
14
|
Klatt T, Markiewicz JT, Sämann C, Knochel P. Strategies To Prepare and Use Functionalized Organometallic Reagents. J Org Chem 2014; 79:4253-69. [DOI: 10.1021/jo500297r] [Citation(s) in RCA: 124] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Thomas Klatt
- Department
Chemie, Ludwig-Maximilians-Universität München, Butenandtstrasse
5-13, Haus F, 81377 München, Germany
| | - John T. Markiewicz
- Department
Chemie, Ludwig-Maximilians-Universität München, Butenandtstrasse
5-13, Haus F, 81377 München, Germany
| | - Christoph Sämann
- Department
Chemie, Ludwig-Maximilians-Universität München, Butenandtstrasse
5-13, Haus F, 81377 München, Germany
| | - Paul Knochel
- Department
Chemie, Ludwig-Maximilians-Universität München, Butenandtstrasse
5-13, Haus F, 81377 München, Germany
| |
Collapse
|