1
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Hamze C, Brossier J, Karaghiosoff K, Godineau E, Knochel P. Selective and Stepwise Functionalization of the Pyridazine Scaffold by Using Thio-Substituted Pyridazine Building Blocks. Chemistry 2023; 29:e202302156. [PMID: 37534401 DOI: 10.1002/chem.202302156] [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: 07/06/2023] [Revised: 07/31/2023] [Accepted: 08/03/2023] [Indexed: 08/04/2023]
Abstract
We described a regioselective tri- and tetra-functionalization of the pyridazine scaffold using two readily available building blocks: 3-alkylthio-6-chloropyridazine and 3,4-bis(methylthio)-6-chloropyridazine by performing selective metalations with TMPMgCl ⋅ LiCl and catalyst-tuned cross-coupling reactions with arylzinc halides. Several of the resulting pyridazines were converted into more elaborated N-heterocycles such as thieno[2,3-c]pyridazines and 1H-pyrazolo[3,4-c]pyridazines.
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Affiliation(s)
- Clémence Hamze
- Department of Chemistry, Ludwig-Maximilians University, Butenandtstraße 5-13, Haus F, 81377, Munich, Germany
| | - Julie Brossier
- Department of Chemistry, Ludwig-Maximilians University, Butenandtstraße 5-13, Haus F, 81377, Munich, Germany
| | - Konstantin Karaghiosoff
- Department of Chemistry, Ludwig-Maximilians University, Butenandtstraße 5-13, Haus F, 81377, Munich, Germany
| | - Edouard Godineau
- Research & Development, Syngenta Crop Protection AG, Schaffhauserstrasse 101, 4332, Stein, Switzerland
| | - Paul Knochel
- Department of Chemistry, Ludwig-Maximilians University, Butenandtstraße 5-13, Haus F, 81377, Munich, Germany
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2
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Ning C, Tao A, Xu J. Design, synthesis, and biological evaluation of 3, 5-disubsituted-1H-pyrazolo[3,4-b]pyridines as multiacting inhibitors against microtubule and kinases. Eur J Med Chem 2023; 259:115687. [PMID: 37544183 DOI: 10.1016/j.ejmech.2023.115687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 07/21/2023] [Accepted: 07/25/2023] [Indexed: 08/08/2023]
Abstract
Combination therapy of kinases inhibitors and chemotherapeutics targeting tubulin dynamics is an important strategy to improve therapeutic efficacy and overcome the resistance to single-target drug therapies. Inspired by this, we report herein the rational design of 3,5-disubsituted-1H-pyrazolo[3,4-b]pyridines as multiacting molecules that are capable of inhibiting tubulin and kinases simultaneously. Among them, 8g showed excellent antiproliferative activities toward a panel of cancer cell lines. 8g strongly inhibited tubulin assembly and demonstrated a potent inhibition toward FLT3 and Abl1 in both enzymatic and cellular assays. 8g caused a cell cycle arrest at G2/M phase, and significantly disrupted HUVEC tube formation. In vivo efficacy studies showed that 8g significantly inhibited tumor growth on the K562 leukemia xenograft model at 10 mg/kg. Collectively our studies suggest that the excellent antiproliferative potency of 8g may be attributed to its potent inhibitory activity against both microtubule and kinases.
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Affiliation(s)
- Chengqing Ning
- Department of Chemistry and Shenzhen Grubbs Institute and Guangdong Provincial Key Laboratory of Catalysis and Shenzhen Key Laboratory of Small Molecule Drug Discovery and Synthesis, Southern University of Science and Technology, Shenzhen, 518055, China; SUSTech Academy for Advanced Interdisciplinary Studies, Shenzhen, 518055, China.
| | - Axiao Tao
- Department of Chemistry and Shenzhen Grubbs Institute and Guangdong Provincial Key Laboratory of Catalysis and Shenzhen Key Laboratory of Small Molecule Drug Discovery and Synthesis, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Jing Xu
- Department of Chemistry and Shenzhen Grubbs Institute and Guangdong Provincial Key Laboratory of Catalysis and Shenzhen Key Laboratory of Small Molecule Drug Discovery and Synthesis, Southern University of Science and Technology, Shenzhen, 518055, China.
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3
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Kumar Rout S, Kastrati A, Jangra H, Schwärzer K, Sunagatullina AS, Garny M, Lima F, Brocklehurst CE, Karaghiosoff K, Zipse H, Knochel P. Reliable Functionalization of 5,6‐Fused Bicyclic N‐Heterocycles Pyrazolopyrimidines and Imidazopyridazines via Zinc and Magnesium Organometallics. Chemistry 2022; 28:e202200733. [PMID: 35384103 PMCID: PMC9321601 DOI: 10.1002/chem.202200733] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Indexed: 12/20/2022]
Abstract
DFT‐calculations allow prediction of the reactivity of uncommon N‐heterocyclic scaffolds of pyrazolo[1,5‐a]pyrimidines and imidazo[1,2‐b]pyridazines and considerably facilitate their functionalization. The derivatization of these N‐heterocycles was realized using Grignard reagents for nucleophilic additions to 5‐chloropyrazolo[1,5‐a]pyrimidines and TMP2Zn ⋅ 2 MgCl2
⋅ 2 LiCl allowed regioselective zincations. In the case of 6‐chloroimidazo[1,2‐b]pyridazine, bases such as TMP2Zn ⋅ MgCl2
⋅ 2 LiCl, in the presence or absence of BF3
⋅ OEt2, led to regioselective metalations at positions 3 or 8. Subsequent functionalizations were achieved with TMPMgCl ⋅ LiCl, producing various polysubstituted derivatives (up to penta‐substitution). X‐ray analysis confirmed the regioselectivity for key functional heterocycles.
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Affiliation(s)
- Saroj Kumar Rout
- Department Chemie Ludwig-Maximilians-Universität München Butenandtstrasse 5–13, Haus F 81377 München Germany
| | - Agonist Kastrati
- Department Chemie Ludwig-Maximilians-Universität München Butenandtstrasse 5–13, Haus F 81377 München Germany
| | - Harish Jangra
- Department Chemie Ludwig-Maximilians-Universität München Butenandtstrasse 5–13, Haus F 81377 München Germany
| | - Kuno Schwärzer
- Department Chemie Ludwig-Maximilians-Universität München Butenandtstrasse 5–13, Haus F 81377 München Germany
| | - Alisa S. Sunagatullina
- Department Chemie Ludwig-Maximilians-Universität München Butenandtstrasse 5–13, Haus F 81377 München Germany
| | - Maximilien Garny
- Department Chemie Ludwig-Maximilians-Universität München Butenandtstrasse 5–13, Haus F 81377 München Germany
| | - Fabio Lima
- Global Discovery Chemistry Novartis Institutes for BioMedical Research 4057 Basel Switzerland
| | - Cara E. Brocklehurst
- Global Discovery Chemistry Novartis Institutes for BioMedical Research 4057 Basel Switzerland
| | - Konstantin Karaghiosoff
- Department Chemie Ludwig-Maximilians-Universität München Butenandtstrasse 5–13, Haus F 81377 München Germany
| | - Hendrik Zipse
- 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
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4
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Eckert P, Sharif S, Organ MG. Salt to Taste: The Critical Roles Played by Inorganic Salts in Organozinc Formation and in the Negishi Reaction. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202010917] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Philip Eckert
- Centre for Catalysis Research and Innovation (CCRI) Department of Chemistry and Biomolecular Sciences University of Ottawa Ottawa Ontario K1N6N5 Canada
| | - Sepideh Sharif
- Centre for Catalysis Research and Innovation (CCRI) Department of Chemistry and Biomolecular Sciences University of Ottawa Ottawa Ontario K1N6N5 Canada
| | - Michael G. Organ
- Centre for Catalysis Research and Innovation (CCRI) Department of Chemistry and Biomolecular Sciences University of Ottawa Ottawa Ontario K1N6N5 Canada
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5
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Eckert P, Sharif S, Organ MG. Salt to Taste: The Critical Roles Played by Inorganic Salts in Organozinc Formation and in the Negishi Reaction. Angew Chem Int Ed Engl 2020; 60:12224-12241. [DOI: 10.1002/anie.202010917] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Indexed: 01/06/2023]
Affiliation(s)
- Philip Eckert
- Centre for Catalysis Research and Innovation (CCRI) Department of Chemistry and Biomolecular Sciences University of Ottawa Ottawa Ontario K1N6N5 Canada
| | - Sepideh Sharif
- Centre for Catalysis Research and Innovation (CCRI) Department of Chemistry and Biomolecular Sciences University of Ottawa Ottawa Ontario K1N6N5 Canada
| | - Michael G. Organ
- Centre for Catalysis Research and Innovation (CCRI) Department of Chemistry and Biomolecular Sciences University of Ottawa Ottawa Ontario K1N6N5 Canada
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6
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Banert K, Hagedorn M, Heck M, Hertel R, Ihle A, Müller I, Pester T, Shoker T, Rablen PR. Synthesis of Trialkylamines with Extreme Steric Hindrance and Their Decay by a Hofmann-like Elimination Reaction. J Org Chem 2020; 85:13630-13643. [DOI: 10.1021/acs.joc.0c01790] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Klaus Banert
- Organic Chemistry, Chemnitz University of Technology, Strasse der Nationen 62, 09111 Chemnitz, Germany
| | - Manfred Hagedorn
- Organic Chemistry, Chemnitz University of Technology, Strasse der Nationen 62, 09111 Chemnitz, Germany
| | - Manuel Heck
- Organic Chemistry, Chemnitz University of Technology, Strasse der Nationen 62, 09111 Chemnitz, Germany
| | - Raphael Hertel
- Organic Chemistry, Chemnitz University of Technology, Strasse der Nationen 62, 09111 Chemnitz, Germany
| | - Andreas Ihle
- Organic Chemistry, Chemnitz University of Technology, Strasse der Nationen 62, 09111 Chemnitz, Germany
| | - Ioana Müller
- Organic Chemistry, Chemnitz University of Technology, Strasse der Nationen 62, 09111 Chemnitz, Germany
| | - Tom Pester
- Organic Chemistry, Chemnitz University of Technology, Strasse der Nationen 62, 09111 Chemnitz, Germany
| | - Tharallah Shoker
- Organic Chemistry, Chemnitz University of Technology, Strasse der Nationen 62, 09111 Chemnitz, Germany
| | - Paul R. Rablen
- Department of Chemistry and Biochemistry, Swarthmore College, 500 College Avenue, Swarthmore, Pennsylvania 19081, United States
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7
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Balkenhohl M, Jangra H, Makarov IS, Yang S, Zipse H, Knochel P. A Predictive Model Towards Site-Selective Metalations of Functionalized Heterocycles, Arenes, Olefins, and Alkanes using TMPZnCl⋅LiCl. Angew Chem Int Ed Engl 2020; 59:14992-14999. [PMID: 32400069 PMCID: PMC7497272 DOI: 10.1002/anie.202005372] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Indexed: 01/02/2023]
Abstract
The development of a predictive model towards site-selective deprotometalation reactions using TMPZnCl⋅LiCl is reported (TMP=2,2,6,6-tetramethylpiperidinyl). The pKa values of functionalized N-, S-, and O-heterocycles, arenes, alkenes, or alkanes were calculated and compared to the experimental deprotonation sites. Large overlap (>80 %) between the calculated and empirical deprotonation sites was observed, showing that thermodynamic factors strongly govern the metalation regioselectivity. In the case of olefins, calculated frozen state energies of the deprotonated substrates allowed a more accurate prediction. Additionally, various new N-heterocycles were analyzed and the metalation regioselectivities rationalized using the predictive model.
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Affiliation(s)
- Moritz Balkenhohl
- Department of ChemistryLudwig-Maximilians-Universität MünchenButenandtstr. 5–1381377MunichGermany
| | - Harish Jangra
- Department of ChemistryLudwig-Maximilians-Universität MünchenButenandtstr. 5–1381377MunichGermany
| | - Ilya S. Makarov
- Department of ChemistryLudwig-Maximilians-Universität MünchenButenandtstr. 5–1381377MunichGermany
| | - Shu‐Mei Yang
- Department of ChemistryNational (Taiwan) Normal University88, Sec. 4, Tingchow RoadTaipei11677Taiwan, Republic of China
| | - Hendrik Zipse
- Department of ChemistryLudwig-Maximilians-Universität MünchenButenandtstr. 5–1381377MunichGermany
| | - Paul Knochel
- Department of ChemistryLudwig-Maximilians-Universität MünchenButenandtstr. 5–1381377MunichGermany
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8
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Balkenhohl M, Jangra H, Makarov IS, Yang S, Zipse H, Knochel P. A Predictive Model Towards Site‐Selective Metalations of Functionalized Heterocycles, Arenes, Olefins, and Alkanes using TMPZnCl⋅LiCl. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202005372] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Moritz Balkenhohl
- Department of Chemistry Ludwig-Maximilians-Universität München Butenandtstr. 5–13 81377 Munich Germany
| | - Harish Jangra
- Department of Chemistry Ludwig-Maximilians-Universität München Butenandtstr. 5–13 81377 Munich Germany
| | - Ilya S. Makarov
- Department of Chemistry Ludwig-Maximilians-Universität München Butenandtstr. 5–13 81377 Munich Germany
| | - Shu‐Mei Yang
- Department of Chemistry National (Taiwan) Normal University 88, Sec. 4, Tingchow Road Taipei 11677 Taiwan, Republic of China
| | - Hendrik Zipse
- Department of Chemistry Ludwig-Maximilians-Universität München Butenandtstr. 5–13 81377 Munich Germany
| | - Paul Knochel
- Department of Chemistry Ludwig-Maximilians-Universität München Butenandtstr. 5–13 81377 Munich Germany
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9
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Lou J, Wang Q, Wu P, Wang H, Zhou YG, Yu Z. Transition-metal mediated carbon-sulfur bond activation and transformations: an update. Chem Soc Rev 2020; 49:4307-4359. [PMID: 32458881 DOI: 10.1039/c9cs00837c] [Citation(s) in RCA: 141] [Impact Index Per Article: 35.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2024]
Abstract
Carbon-sulfur bond cross-coupling has become more and more attractive as an alternative protocol to establish carbon-carbon and carbon-heteroatom bonds. Diverse transformations through transition-metal-catalyzed C-S bond activation and cleavage have recently been developed. This review summarizes the advances in transition-metal-catalyzed cross-coupling via carbon-sulfur bond activation and cleavage since late 2012 as an update of the critical review on the same topic published in early 2013 (Chem. Soc. Rev., 2013, 42, 599-621), which is presented by the categories of organosulfur compounds, that is, thioesters, thioethers including heteroaryl, aryl, vinyl, alkyl, and alkynyl sulfides, ketene dithioacetals, sulfoxides including DMSO, sulfones, sulfonyl chlorides, sulfinates, thiocyanates, sulfonium salts, sulfonyl hydrazides, sulfonates, thiophene-based compounds, and C[double bond, length as m-dash]S functionality-bearing compounds such as thioureas, thioamides, and carbon disulfide, as well as the mechanistic insights. An overview of C-S bond cleavage reactions with stoichiometric transition-metal reagents is briefly given. Theoretical studies on the reactivity of carbon-sulfur bonds by DFT calculations are also discussed.
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Affiliation(s)
- Jiang Lou
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, P. R. China. and University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Quannan Wang
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, P. R. China. and University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Ping Wu
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, P. R. China. and University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Hongmei Wang
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, P. R. China.
| | - Yong-Gui Zhou
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, P. R. China.
| | - Zhengkun Yu
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, P. R. China. and State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 354 Fenglin Road, Shanghai 200032, P. R. China
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10
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Ziegler DS, Greiner R, Lumpe H, Kqiku L, Karaghiosoff K, Knochel P. Directed Zincation or Magnesiation of the 2-Pyridone and 2,7-Naphthyridone Scaffold Using TMP Bases. Org Lett 2018; 19:5760-5763. [PMID: 29039957 DOI: 10.1021/acs.orglett.7b02690] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
A regioselective zincation of the 2-pyridone and 2,7-naphthyridone scaffolds has been developed. Zincations of the methoxyethoxymethyl (MEM)-protected compounds using TMP2Zn·2MgCl2·2LiCl (TMP = 2,2,6,6-tetramethylpiperidyl) followed by trapping with electrophiles provided functionalized 2-pyridones and 2,7-naphthyridones. I/Mg exchange of iodinated 2-pyridone and 2,7-naphthyridone using i-PrMgCl·LiCl afforded magnesiated intermediates that reacted with electrophiles. A second magnesiation of the 2-pyridone scaffold was achieved by using TMPMgCl·LiCl. Additionally, we report CoCl2-catalyzed cross-couplings of the 1-chloro-2,7-naphthyridines with arylzinc halides.
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Affiliation(s)
- Dorothée S Ziegler
- Department of Chemistry, Ludwig-Maximilians-University Munich , Butenandtstr. 5-13, 81377 Munich, Germany
| | - Robert Greiner
- Department of Chemistry, Ludwig-Maximilians-University Munich , Butenandtstr. 5-13, 81377 Munich, Germany
| | - Henning Lumpe
- Department of Chemistry, Ludwig-Maximilians-University Munich , Butenandtstr. 5-13, 81377 Munich, Germany
| | - Laura Kqiku
- Department of Chemistry, Ludwig-Maximilians-University Munich , Butenandtstr. 5-13, 81377 Munich, Germany
| | - Konstantin Karaghiosoff
- Department of Chemistry, Ludwig-Maximilians-University Munich , Butenandtstr. 5-13, 81377 Munich, Germany
| | - Paul Knochel
- Department of Chemistry, Ludwig-Maximilians-University Munich , Butenandtstr. 5-13, 81377 Munich, Germany
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11
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Banert K, Heck M, Ihle A, Kronawitt J, Pester T, Shoker T. Steric Hindrance Underestimated: It is a Long, Long Way to Tri- tert-alkylamines. J Org Chem 2018; 83:5138-5148. [PMID: 29630365 DOI: 10.1021/acs.joc.8b00496] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Ten different processes (Methods A-J) were tested to prepare tertiary amines bearing bulky alkyl groups. In particular, SN1 alkylation of secondary amines with the help of 1-adamantyl triflate (Method D) and reaction of N-chlorodialkylamines with organometallic reagents (Method H), but also attack of the latter reagents at iminium salts, which were generated in situ by N-alkylation of imines (Method J), led to trialkylamines with unprecedented steric congestion. These products showed a restriction of the rotation about the C-N bond. Consequently, equilibration of rotamers was slow on the NMR time scale resulting in distinguishable sets of NMR data at room temperature. Furthermore, tertiary amines with bulky alkyl substituents underwent Hofmann-like elimination when heating in toluene to form an olefin and a secondary amine. Since the tendency to take part in this decay reaction correlated with the degree of steric hindrance around the nitrogen atom, Hofmann elimination at ambient temperature, which made the isolation of the tertiary amine difficult, was observed in special cases.
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Affiliation(s)
- Klaus Banert
- Chemnitz University of Technology , Organic Chemistry , Strasse der Nationen 62 , 09111 Chemnitz , Germany
| | - Manuel Heck
- Chemnitz University of Technology , Organic Chemistry , Strasse der Nationen 62 , 09111 Chemnitz , Germany
| | - Andreas Ihle
- Chemnitz University of Technology , Organic Chemistry , Strasse der Nationen 62 , 09111 Chemnitz , Germany
| | - Julia Kronawitt
- Chemnitz University of Technology , Organic Chemistry , Strasse der Nationen 62 , 09111 Chemnitz , Germany
| | - Tom Pester
- Chemnitz University of Technology , Organic Chemistry , Strasse der Nationen 62 , 09111 Chemnitz , Germany
| | - Tharallah Shoker
- Chemnitz University of Technology , Organic Chemistry , Strasse der Nationen 62 , 09111 Chemnitz , Germany
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12
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Otsuka S, Yorimitsu H. Synthesis of 4-aryl- and 4-acyl-1,3-dithiole-2-thiones via deprotonative zincation of 1,3-dithiole-2-thione. HETEROATOM CHEMISTRY 2018. [DOI: 10.1002/hc.21432] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Shinya Otsuka
- Department of Chemistry; Graduate School of Science; Kyoto University; Kyoto Japan
| | - Hideki Yorimitsu
- Department of Chemistry; Graduate School of Science; Kyoto University; Kyoto Japan
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13
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Liu C, Wang Q. Alkenylation of C(sp
3
)−H Bonds by Zincation/Copper‐Catalyzed Cross‐Coupling with Iodonium Salts. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201713278] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Chuan Liu
- French Family Science Center Department of Chemistry Duke University 124 Science Drive Durham NC 27708 USA
- Current address: HitGen Ltd. Tianfu Life Science Park 88 South Keyuan Road Chengdu 610041 P. R. China
| | - Qiu Wang
- French Family Science Center Department of Chemistry Duke University 124 Science Drive Durham NC 27708 USA
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14
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Liu C, Wang Q. Alkenylation of C(sp 3 )-H Bonds by Zincation/Copper-Catalyzed Cross-Coupling with Iodonium Salts. Angew Chem Int Ed Engl 2018; 57:4727-4731. [PMID: 29479782 DOI: 10.1002/anie.201713278] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2017] [Revised: 02/06/2018] [Indexed: 12/20/2022]
Abstract
α-Vinylation of phosphonates, phosphine oxides, sulfones, sulfonamides, and sulfoxides has been achieved by selective C-H zincation and copper-catalyzed C(sp3 )-C(sp2 ) cross-coupling reaction using vinylphenyliodonium salts. The vinylation transformation proceeds in high efficiency and stereospecificity under mild reaction conditions. This zincative cross-coupling reaction represents a general alkenylation strategy, which is also applicable for α-alkenylation of esters, amides, and nitriles in the synthesis of β,γ-unsaturated carbonyl compounds.
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Affiliation(s)
- Chuan Liu
- French Family Science Center, Department of Chemistry, Duke University, 124 Science Drive, Durham, NC, 27708, USA.,Current address: HitGen Ltd., Tianfu Life Science Park, 88 South Keyuan Road, Chengdu, 610041, P. R. China
| | - Qiu Wang
- French Family Science Center, Department of Chemistry, Duke University, 124 Science Drive, Durham, NC, 27708, USA
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15
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Hendrick CE, Bitting KJ, Cho S, Wang Q. Site-Selective Copper-Catalyzed Amination and Azidation of Arenes and Heteroarenes via Deprotonative Zincation. J Am Chem Soc 2017; 139:11622-11628. [PMID: 28753007 PMCID: PMC5685551 DOI: 10.1021/jacs.7b07661] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Arene amination is achieved by site-selective C-H zincation followed by copper-catalyzed coupling with O-benzoylhydroxylamines under mild conditions. Key to this success is ortho-zincation mediated by lithium amidodiethylzincate base that is effective for a wide range of arenes, including nonactivated arenes bearing simple functionalities such as fluoride, chloride, ester, amide, ether, nitrile, and trifluoromethyl groups as well as heteroarenes including indole, thiophene, pyridine, and isoquinoline. An analogous C-H azidation is also accomplished using azidoiodinane for direct introduction of a useful azide group onto a broad scope of arenes and heteroarenes. These new transformations offer rapid access to valuable and diverse chemical space of aminoarenes. Their broad applications in organic synthesis and drug discovery are demonstrated in the synthesis of novel analogues of natural product (-)-nicotine and antidepressant sertraline by late-stage amination and azidation reactions.
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Affiliation(s)
- Charles E. Hendrick
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - Katie J. Bitting
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - Seoyoung Cho
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - Qiu Wang
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
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16
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Diyanatizadeh MH, Yavari I. Synthesis of spiro heterocyclic systems from 2-(3-oxoisobenzofuran-1(3 H)-ylidene)malononitrile and binucleophiles. JOURNAL OF CHEMICAL RESEARCH 2017. [DOI: 10.3184/174751917x14944355549159] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The reaction of 2-(3-oxoisobenzofuran-1(3 H)-ylidene)malononitrile, generated from phthalic anhydride and malononitrile, with different binucleophiles led to the formation of spiro heterocycles possessing a phthalide ring system in good yields.
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Affiliation(s)
| | - Issa Yavari
- Department of Chemistry, Tarbiat Modares University, PO Box 14115-175, Tehran, Iran
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17
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Abstract
Azines, which are six-membered aromatic compounds containing one or more nitrogen atoms, serve as ubiquitous structural cores of aromatic species with important applications in biological and materials sciences. Among a variety of synthetic approaches toward azines, C-H functionalization represents the most rapid and atom-economical transformation, and it is advantageous for the late-stage functionalization of azine-containing functional molecules. Since azines have several C-H bonds with different reactivities, the development of new reactions that allow for the functionalization of azines in a regioselective fashion has comprised a central issue. This review describes recent advances in the C-H functionalization of azines categorized as follows: (1) SNAr reactions, (2) radical reactions, (3) deprotonation/functionalization, and (4) metal-catalyzed reactions.
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Affiliation(s)
- Kei Murakami
- Institute of Transformative Bio-Molecules (WPI-ITbM) and Graduate School of Science, and ‡JST-ERATO, Itami Molecular Nanocarbon Project, Nagoya University , Chikusa, Nagoya 464-8602, Japan
| | - Shuya Yamada
- Institute of Transformative Bio-Molecules (WPI-ITbM) and Graduate School of Science, and ‡JST-ERATO, Itami Molecular Nanocarbon Project, Nagoya University , Chikusa, Nagoya 464-8602, Japan
| | - Takeshi Kaneda
- Institute of Transformative Bio-Molecules (WPI-ITbM) and Graduate School of Science, and ‡JST-ERATO, Itami Molecular Nanocarbon Project, Nagoya University , Chikusa, Nagoya 464-8602, Japan
| | - Kenichiro Itami
- Institute of Transformative Bio-Molecules (WPI-ITbM) and Graduate School of Science, and ‡JST-ERATO, Itami Molecular Nanocarbon Project, Nagoya University , Chikusa, Nagoya 464-8602, Japan
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18
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Castelló-Micó A, Nafe J, Higashida K, Karaghiosoff K, Gingras M, Knochel P. Selective Metalations of 1,4-Dithiins and Condensed Analogues Using TMP-Magnesium and -Zinc Bases. Org Lett 2016; 19:360-363. [DOI: 10.1021/acs.orglett.6b03539] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Alicia Castelló-Micó
- Department
Chemie, Ludwig-Maximilians-Universität, Butenandtstrasse 5-13, 81377 München, Germany
| | - Julia Nafe
- Department
Chemie, Ludwig-Maximilians-Universität, Butenandtstrasse 5-13, 81377 München, Germany
| | - Kosuke Higashida
- Department
Chemie, Ludwig-Maximilians-Universität, Butenandtstrasse 5-13, 81377 München, Germany
| | - Konstantin Karaghiosoff
- Department
Chemie, Ludwig-Maximilians-Universität, Butenandtstrasse 5-13, 81377 München, Germany
| | - Marc Gingras
- CNRS, Aix-Marseille Université, CINAM UMR 7325, 163 Avenue de Luminy, 13288 Marseille, France
| | - Paul Knochel
- Department
Chemie, Ludwig-Maximilians-Universität, Butenandtstrasse 5-13, 81377 München, Germany
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19
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Haas D, Sustac-Roman D, Schwarz S, Knochel P. Directed Zincation with TMPZnCl·LiCl and Further Functionalization of the Tropolone Scaffold. Org Lett 2016; 18:6380-6383. [DOI: 10.1021/acs.orglett.6b03270] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Diana Haas
- Department of Chemistry, Ludwig-Maximilians-University Munich, Butenandtstr. 5-13, 81377 Munich, Germany
| | - Daniela Sustac-Roman
- Department of Chemistry, Ludwig-Maximilians-University Munich, Butenandtstr. 5-13, 81377 Munich, Germany
| | - Sophia Schwarz
- Department of Chemistry, Ludwig-Maximilians-University Munich, Butenandtstr. 5-13, 81377 Munich, Germany
| | - Paul Knochel
- Department of Chemistry, Ludwig-Maximilians-University Munich, Butenandtstr. 5-13, 81377 Munich, Germany
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21
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Knauber T, Tucker J. Palladium Catalyzed Monoselective α-Arylation of Sulfones and Sulfonamides with 2,2,6,6-Tetramethylpiperidine·ZnCl·LiCl Base and Aryl Bromides. J Org Chem 2016; 81:5636-48. [PMID: 27303950 DOI: 10.1021/acs.joc.6b01062] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A palladium catalyzed Negishi-type α-arylation of sulfones and sulfonamides with a broad range of aryl bromides has been developed. The substrates are selectively metalated in situ with tmp·ZnCl·LiCl base (tmp: 2,2,6,6-tetramethylpiperidine) and cross-coupled in the presence of a catalyst system that is generated from Pd(dba)2 and XPhos. Electron-deficient, electron-rich, and heterocyclic aryl bromides have been successfully cross-coupled, and sensitive functional groups are well tolerated. Simple aryl bromides are converted overnight at 60 °C in THF while heteroaryl bromides are efficiently coupled within 2 h at 130 °C in a microwave reactor. The desired monoarylated α-branched benzyl sulfones and sulfonamides were obtained in good yields, and overarylation was not detected. The procedure is ideal for late stage functionalization in parallel medicinal chemistry.
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Affiliation(s)
- Thomas Knauber
- Worldwide Medicinal Chemistry, Pfizer Worldwide Research and Development , Groton, Connecticut 06340, United States
| | - Joseph Tucker
- Worldwide Medicinal Chemistry, Pfizer Worldwide Research and Development , Groton, Connecticut 06340, United States
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22
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Ganiek MA, Becker MR, Ketels M, Knochel P. Continuous Flow Magnesiation or Zincation of Acrylonitriles, Acrylates, and Nitroolefins. Application to the Synthesis of Butenolides. Org Lett 2016; 18:828-31. [DOI: 10.1021/acs.orglett.6b00086] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Maximilian A. Ganiek
- Department
of Chemistry, Ludwig-Maximilians-Universität, Butenandtstr. 5-13, 81377 Munich, Germany
| | - Matthias R. Becker
- Department
of Chemistry, Ludwig-Maximilians-Universität, Butenandtstr. 5-13, 81377 Munich, Germany
| | - Marthe Ketels
- Department
of Chemistry, Ludwig-Maximilians-Universität, Butenandtstr. 5-13, 81377 Munich, Germany
| | - Paul Knochel
- Department
of Chemistry, Ludwig-Maximilians-Universität, Butenandtstr. 5-13, 81377 Munich, Germany
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23
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Haas D, Hammann JM, Greiner R, Knochel P. Recent Developments in Negishi Cross-Coupling Reactions. ACS Catal 2016. [DOI: 10.1021/acscatal.5b02718] [Citation(s) in RCA: 264] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Diana Haas
- Ludwig-Maximilians-University, Department of Chemistry and Pharmacy, Butenandtstr. 5-13, 81377 Munich, Germany
| | - Jeffrey M. Hammann
- Ludwig-Maximilians-University, Department of Chemistry and Pharmacy, Butenandtstr. 5-13, 81377 Munich, Germany
| | - Robert Greiner
- Ludwig-Maximilians-University, Department of Chemistry and Pharmacy, Butenandtstr. 5-13, 81377 Munich, Germany
| | - Paul Knochel
- Ludwig-Maximilians-University, Department of Chemistry and Pharmacy, Butenandtstr. 5-13, 81377 Munich, Germany
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24
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Gao K, Otsuka S, Baralle A, Nogi K, Yorimitsu, H, Osuka A. Cross-coupling of Aryl Sulfides Powered by N-Heterocyclic Carbene Ligands. J SYN ORG CHEM JPN 2016. [DOI: 10.5059/yukigoseikyokaishi.74.1119] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
| | | | | | | | - Hideki Yorimitsu,
- Department of Chemistry, Graduate School of Science, Kyoto University
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25
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Nafe J, Auras F, Karaghiosoff K, Bein T, Knochel P. Selective Functionalization of Tetrathiafulvalene Using Mg- and Zn-TMP-Bases: Preparation of Mono-, Di-, Tri-, and Tetrasubstituted Derivatives. Org Lett 2015; 17:5356-9. [PMID: 26469280 PMCID: PMC4797621 DOI: 10.1021/acs.orglett.5b02715] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Indexed: 11/30/2022]
Abstract
The tetrathiafulvalene-scaffold (TTF) reacts selectively in allylation, acylation, arylation, halogenation, and thiolation reactions via magnesium or zinc derivatives that are obtained by a direct metalation with Mg- and Zn-TMP-bases (TMP = 2,2,6,6-tetramethylpiperidyl). This stepwise functionalization provides access to a range of new mono-, di-, tri-, and tetra-functionalized TTF-derivatives and allows for fine-tuning of their energy levels.
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Affiliation(s)
- Julia Nafe
- Department
of Chemistry, Ludwig-Maximilians-Universität, Butenandtstrasse 5-13, 81377 München, Germany
| | - Florian Auras
- Department
of Chemistry, Ludwig-Maximilians-Universität, Butenandtstrasse 5-13, 81377 München, Germany
| | - Konstantin Karaghiosoff
- Department
of Chemistry, Ludwig-Maximilians-Universität, Butenandtstrasse 5-13, 81377 München, Germany
| | - Thomas Bein
- Department
of Chemistry, Ludwig-Maximilians-Universität, Butenandtstrasse 5-13, 81377 München, Germany
| | - Paul Knochel
- Department
of Chemistry, Ludwig-Maximilians-Universität, Butenandtstrasse 5-13, 81377 München, Germany
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26
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Palladium-Catalyzed Zinc-Amide-Mediated CH Arylation of Fluoroarenes and Heteroarenes with Aryl Sulfides. Chemistry 2015; 21:14703-7. [DOI: 10.1002/chem.201502101] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Indexed: 12/23/2022]
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27
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Quinio P, François C, Escribano Cuesta A, Steib AK, Achrainer F, Zipse H, Karaghiosoff K, Knochel P. Preparation of Tri- and Tetrasubstituted Allenes via Regioselective Lateral Metalation of Benzylic (Trimethylsilyl)alkynes Using TMPZnCl·LiCl. Org Lett 2015; 17:1010-3. [DOI: 10.1021/acs.orglett.5b00114] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Pauline Quinio
- Department
Chemie, Ludwig-Maximilians-Universität, Butenandtstrasse 5-13, 81377 München, Germany
| | - Cyril François
- Department
Chemie, Ludwig-Maximilians-Universität, Butenandtstrasse 5-13, 81377 München, Germany
| | - Ana Escribano Cuesta
- Department
Chemie, Ludwig-Maximilians-Universität, Butenandtstrasse 5-13, 81377 München, Germany
| | - Andreas K. Steib
- Department
Chemie, Ludwig-Maximilians-Universität, Butenandtstrasse 5-13, 81377 München, Germany
| | - Florian Achrainer
- Department
Chemie, Ludwig-Maximilians-Universität, Butenandtstrasse 5-13, 81377 München, Germany
| | - Hendrik Zipse
- Department
Chemie, Ludwig-Maximilians-Universität, Butenandtstrasse 5-13, 81377 München, Germany
| | - Konstantin Karaghiosoff
- Department
Chemie, Ludwig-Maximilians-Universität, Butenandtstrasse 5-13, 81377 München, Germany
| | - Paul Knochel
- Department
Chemie, Ludwig-Maximilians-Universität, Butenandtstrasse 5-13, 81377 München, Germany
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28
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Haas D, Hofmayer MS, Bresser T, Knochel P. Zincation of 4,4-dimethyloxazoline using TMPZnCl·LiCl. A new preparation of 2-aryloxazolines. Chem Commun (Camb) 2015; 51:6415-7. [DOI: 10.1039/c5cc01144b] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
4,4-Dimethyloxazoline is directly zincated using TMPZnCl·LiCl and further functionalized by Pd-catalyzed cross-couplings, as well as Cu-mediated acylation and allylation reactions.
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Affiliation(s)
- Diana Haas
- Ludwig Maximilians-University Munich
- Department of Chemistry
- 81377 München
- Germany
| | | | - Tomke Bresser
- Ludwig Maximilians-University Munich
- Department of Chemistry
- 81377 München
- Germany
| | - Paul Knochel
- Ludwig Maximilians-University Munich
- Department of Chemistry
- 81377 München
- Germany
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29
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McDonald SL, Hendrick CE, Wang Q. Copper-catalyzed electrophilic amination of heteroarenes and arenes by C-H zincation. Angew Chem Int Ed Engl 2014; 53:4667-70. [PMID: 24668522 PMCID: PMC4668583 DOI: 10.1002/anie.201311029] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Revised: 02/21/2014] [Indexed: 01/28/2023]
Abstract
Direct amination of heteroarenes and arenes has been achieved in a one-pot CH zincation/copper-catalyzed electrophilic amination procedure. This amination method provides an efficient and rapid approach to access a diverse range of heteroaromatic and aromatic amines including those previously inaccessible using CH amination methods. The mild reaction conditions and good functional-group compatibility demonstrate its great potential for the synthesis of important and complex amines.
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Affiliation(s)
| | | | - Qiu Wang
- Department of Chemistry, Duke University Durham, NC 27708-0346 (USA)
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30
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McDonald SL, Hendrick CE, Wang Q. Copper-Catalyzed Electrophilic Amination of Heteroarenes and Arenes by CH Zincation. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201311029] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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31
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Haas D, Mosrin M, Knochel P. Regioselective Functionalization of the Oxazole Scaffold Using TMP-Bases of Mg and Zn. Org Lett 2013; 15:6162-5. [DOI: 10.1021/ol403019c] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Diana Haas
- Department of Chemistry, Ludwig-Maximilians-University, Butenandtstrasse 5-13, 81377 München, Germany, and Bayer CropScience AG, Industriepark Höchst, 65926 Frankfurt am Main, Germany
| | - Marc Mosrin
- Department of Chemistry, Ludwig-Maximilians-University, Butenandtstrasse 5-13, 81377 München, Germany, and Bayer CropScience AG, Industriepark Höchst, 65926 Frankfurt am Main, Germany
| | - Paul Knochel
- Department of Chemistry, Ludwig-Maximilians-University, Butenandtstrasse 5-13, 81377 München, Germany, and Bayer CropScience AG, Industriepark Höchst, 65926 Frankfurt am Main, Germany
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32
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Unsinn A, Wunderlich SH, Jana A, Karaghiosoff K, Knochel P. A convenient alumination of functionalized aromatics by using the frustrated Lewis pair Et3 Al and TMPMgCl⋅LiCl. Chemistry 2013; 19:14687-96. [PMID: 24027191 DOI: 10.1002/chem.201301869] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Indexed: 11/07/2022]
Abstract
A straightforward and efficient alumination of functionalized arenes by using the frustrated Lewis pair Et3 Al and TMPMgCl⋅LiCl (TMP=2,2,6,6-tetramethylpiperidyl) has been developed. In particular, halogenated electron-rich aromatics can be smoothly functionalized by using the frustrated Lewis pair Et3 Al and TMPMgCl⋅LiCl. Compared with previously described alumination methods, this procedure avoids extensive cooling and the need for an excess of base. This in situ procedure has proven to be most practical and allows for regio- and chemoselective metalation of a wide range of aromatics with sensitive functional groups (CONEt2 , CO2 Me, CN, OCONMe2 ) or halogens (F, Cl, Br, I). The resulting aromatic aluminates, which were characterized by using NMR spectroscopy, were subjected to allylations, acylations, and palladium-catalyzed cross-coupling reactions after transmetalation to zinc. It was shown that the nature of the Zn salt used for transmetalation is crucial. Thus, compared with ZnCl2 (2 equiv), the use of Zn(OPiv)2 (2 equiv; OPiv=pivalate) allows the subsequent quenching reactions to be performed with only a slight excess of electrophile (1.2 equiv) and provides interesting functionalized aromatics in good yields.
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Affiliation(s)
- Andreas Unsinn
- Department Chemie, Ludwig-Maximilians-Universität München, Butenandtstrasse 5-13, Haus F, 81377 München (Germany), Fax: (+49) 89-2180-77680
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33
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Groll K, Manolikakes SM, du Jourdin XM, Jaric M, Bredihhin A, Karaghiosoff K, Carell T, Knochel P. Regioselektive Metallierungen von Pyrimidinen und Pyrazinen mit frustrierten Lewis-Paaren aus BF3⋅OEt2und sterisch gehinderten Mg- und Zn-Amidbasen. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201301694] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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34
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Groll K, Manolikakes SM, du Jourdin XM, Jaric M, Bredihhin A, Karaghiosoff K, Carell T, Knochel P. Regioselective Metalations of Pyrimidines and Pyrazines by Using Frustrated Lewis Pairs of BF3⋅OEt2and Hindered Magnesium- and Zinc-Amide Bases. Angew Chem Int Ed Engl 2013; 52:6776-80. [DOI: 10.1002/anie.201301694] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Revised: 04/02/2013] [Indexed: 12/23/2022]
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35
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Unsinn A, Rohbogner CJ, Knochel P. Directed Magnesiation of Polyhaloaromatics using the Tetramethylpiperidylmagnesium Reagents TMP2Mg⋅2 LiCl and TMPMgCl⋅LiCl. Adv Synth Catal 2013. [DOI: 10.1002/adsc.201300185] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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