1
|
Rekhroukh F, Zhang L, Kong RY, White AJP, Crimmin MR. Stereoselective insertion of cyclopropenes into Mg-Mg bonds. Chem Commun (Camb) 2022; 58:8282-8285. [PMID: 35791826 DOI: 10.1039/d2cc02931f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The reaction of cyclopropenes with compounds containing Mg-Mg bonds is reported. 1,2-Dimagnesiation occurs exclusively by syn-addition to the least hindered face of the alkene forming a single diastereomeric product. DFT calculations support a concerted and stereoselective mechanism. These findings shed new light on the stereochemistry of reactions involving magnesium reagents.
Collapse
Affiliation(s)
- Feriel Rekhroukh
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, 82 Wood Lane, Shepherds Bush, London, W12 0BZ, UK.
| | - Linxing Zhang
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, 82 Wood Lane, Shepherds Bush, London, W12 0BZ, UK. .,Shenzhen Bay Laboratory, Shenzhen, 518132, P. R. China
| | - Richard Y Kong
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, 82 Wood Lane, Shepherds Bush, London, W12 0BZ, UK.
| | - Andrew J P White
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, 82 Wood Lane, Shepherds Bush, London, W12 0BZ, UK.
| | - Mark R Crimmin
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, 82 Wood Lane, Shepherds Bush, London, W12 0BZ, UK.
| |
Collapse
|
2
|
Sasaki M, Shimabara R, Takegawa T, Kotomori Y, Otani Y, Ohwada T, Takeda K. Steric Course of Deprotonation/Substitution of Chelating/Dipole-Stabilizing-Group-Substituted α-Amino- and α-Oxynitriles. European J Org Chem 2018. [DOI: 10.1002/ejoc.201800484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Michiko Sasaki
- Department of Synthetic Organic Chemistry; Institute of Biomedical & Health Science; Hiroshima University; 1-2-3 Kasumi 734-8553 Minami-Ku, Hiroshima Japan
| | - Rumiko Shimabara
- Department of Synthetic Organic Chemistry; Institute of Biomedical & Health Science; Hiroshima University; 1-2-3 Kasumi 734-8553 Minami-Ku, Hiroshima Japan
| | - Tomo Takegawa
- Department of Synthetic Organic Chemistry; Institute of Biomedical & Health Science; Hiroshima University; 1-2-3 Kasumi 734-8553 Minami-Ku, Hiroshima Japan
| | - Yuri Kotomori
- Department of Synthetic Organic Chemistry; Institute of Biomedical & Health Science; Hiroshima University; 1-2-3 Kasumi 734-8553 Minami-Ku, Hiroshima Japan
| | - Yuko Otani
- Graduate School of Pharmaceutical Sciences; The University of Tokyo; 7-3-1 Hongo 113-0033 Bunkyo-Ku, Tokyo Japan
| | - Tomohiko Ohwada
- Graduate School of Pharmaceutical Sciences; The University of Tokyo; 7-3-1 Hongo 113-0033 Bunkyo-Ku, Tokyo Japan
| | - Kei Takeda
- Department of Synthetic Organic Chemistry; Institute of Biomedical & Health Science; Hiroshima University; 1-2-3 Kasumi 734-8553 Minami-Ku, Hiroshima Japan
| |
Collapse
|
3
|
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
|
4
|
|
5
|
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
|
6
|
Kotomori Y, Sasaki M, Kawahata M, Yamaguchi K, Takeda K. Stereochemical Course of Deprotonation-Acylation of N-Boc- and N-Carbamoyl-2-cyano-6-methylpiperidines. J Org Chem 2015; 80:11013-20. [PMID: 26457453 DOI: 10.1021/acs.joc.5b02178] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The stereochemical course of electrophilic substitution of α-nitrile metallocarbanions generated by deprotonation from N-Boc- and N-carbamoyl-2-cyano-6-methylpiperidines was investigated. Deprotonation in the presence of an electrophile taking advantage of the high acidity of α-nitrile protons allowed examination of the effects of a chelating group on the nitrogen atom, a countercation, and the reactivity of an electrophile on the steric course. Analyses of reactions using aroyl chlorides and methyl iodide revealed the following: (1) the substitution reactions basically proceed with retention of configuration, (2) the extent of an inversion product increases with decreasing chelating ability of the N-substituent and with increasing leaving ability (ionic character) of a countercation (Li, Na, K) of the anionic species, and (3) the use of a more reactive electrophile results in an increase of the retention product.
Collapse
Affiliation(s)
- Yuri Kotomori
- Department of Synthetic Organic Chemistry, Institute of Biomedical & Health Sciences, Hiroshima University , 1-2-3 Kasumi, Minami-Ku, Hiroshima 734-8553, Japan
| | - Michiko Sasaki
- Department of Synthetic Organic Chemistry, Institute of Biomedical & Health Sciences, Hiroshima University , 1-2-3 Kasumi, Minami-Ku, Hiroshima 734-8553, Japan
| | - Masatoshi Kawahata
- Pharmaceutical Sciences at Kagawa Campus, Tokushima Bunri University , 1314-1 Shido, Sanuki, Kagawa 769-2193, Japan
| | - Kentaro Yamaguchi
- Pharmaceutical Sciences at Kagawa Campus, Tokushima Bunri University , 1314-1 Shido, Sanuki, Kagawa 769-2193, Japan
| | - Kei Takeda
- Department of Synthetic Organic Chemistry, Institute of Biomedical & Health Sciences, Hiroshima University , 1-2-3 Kasumi, Minami-Ku, Hiroshima 734-8553, Japan
| |
Collapse
|
7
|
Affiliation(s)
- Xun Yang
- Department of Chemistry and
Biochemistry, Duquesne University, Pittsburgh, Pennsylvania 15282-1530, United States
| | - Dinesh Nath
- Department of Chemistry and
Biochemistry, Duquesne University, Pittsburgh, Pennsylvania 15282-1530, United States
| | - Fraser F. Fleming
- Department of Chemistry and
Biochemistry, Duquesne University, Pittsburgh, Pennsylvania 15282-1530, United States
| |
Collapse
|
8
|
Sasaki M, Takegawa T, Sakamoto K, Kotomori Y, Otani Y, Ohwada T, Kawahata M, Yamaguchi K, Takeda K. Enantiodivergent Deprotonation/Acylation of α-Amino Nitriles. Angew Chem Int Ed Engl 2013; 52:12956-60. [DOI: 10.1002/anie.201306443] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2013] [Revised: 09/03/2013] [Indexed: 11/06/2022]
|
9
|
Sasaki M, Takegawa T, Sakamoto K, Kotomori Y, Otani Y, Ohwada T, Kawahata M, Yamaguchi K, Takeda K. Enantiodivergent Deprotonation/Acylation of α-Amino Nitriles. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201306443] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
10
|
Gao M, Patwardhan NN, Carlier PR. Stereochemical Inversion of a Cyano-Stabilized Grignard Reagent: Remarkable Effects of the Ethereal Solvent Structure and Concentration. J Am Chem Soc 2013; 135:14390-400. [DOI: 10.1021/ja407348s] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ming Gao
- Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Neeraj N. Patwardhan
- Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Paul R. Carlier
- Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, United States
| |
Collapse
|
11
|
Chirality transfer in Brook rearrangement-mediated SE2′ solvolytic protonation and its use in estimation of the propensity for racemization of the α-lithiocarbanions of the substituents. Tetrahedron 2013. [DOI: 10.1016/j.tet.2013.05.043] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
12
|
Barker G, Alshawish MR, Skilbeck MC, Coldham I. Remarkable Configurational Stability of Magnesiated Nitriles. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201303442] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
13
|
Barker G, Alshawish MR, Skilbeck MC, Coldham I. Remarkable Configurational Stability of Magnesiated Nitriles. Angew Chem Int Ed Engl 2013; 52:7700-3. [DOI: 10.1002/anie.201303442] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Indexed: 11/08/2022]
|
14
|
Hellmann G, Hack A, Thiemermann E, Luche O, Raabe G, Gais HJ. Chiral Fluorinated α-Sulfonyl Carbanions: Enantioselective Synthesis and Electrophilic Capture, Racemization Dynamics, and Structure. Chemistry 2013; 19:3869-97. [DOI: 10.1002/chem.201204014] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Indexed: 11/06/2022]
|
15
|
Nath D, Fleming FF. Sulfinylnitriles: Sulfinyl-Metal Exchange-Alkylation Strategies. Chemistry 2012; 19:2023-9. [DOI: 10.1002/chem.201203174] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2012] [Indexed: 11/09/2022]
|
16
|
Mycka RJ, Duez S, Bernhardt S, Heppekausen J, Knochel P, Fleming FF. Cyclohexylcarbonitriles: Diastereoselective Arylations with TMPZnCl·LiCl. J Org Chem 2012; 77:7671-6. [DOI: 10.1021/jo301127n] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Robert J. Mycka
- Department of Chemistry and
Biochemistry, Duquesne University, Pittsburgh,
Pennsylvania 15282-1530, United States
| | - Stéphanie Duez
- Department Chemie, Ludwig-Maximilians-Universität, Butenandtstrasse
5-13, 81377, München, Germany
| | - Sebastian Bernhardt
- Department Chemie, Ludwig-Maximilians-Universität, Butenandtstrasse
5-13, 81377, München, Germany
| | - Johannes Heppekausen
- Department Chemie, Ludwig-Maximilians-Universität, Butenandtstrasse
5-13, 81377, München, Germany
| | - Paul Knochel
- Department Chemie, Ludwig-Maximilians-Universität, Butenandtstrasse
5-13, 81377, München, Germany
| | - Fraser F. Fleming
- Department of Chemistry and
Biochemistry, Duquesne University, Pittsburgh,
Pennsylvania 15282-1530, United States
| |
Collapse
|