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Kremsmair A, Sunagatullina AS, Bole LJ, Mastropierro P, Graßl S, Wilke HR, Godineau E, Hevia E, Knochel P. Exploiting Coordination Effects for the Regioselective Zincation of Diazines Using TMPZnX⋅LiX (X=Cl, Br). Angew Chem Int Ed Engl 2022; 61:e202210491. [PMID: 35943036 PMCID: PMC9826189 DOI: 10.1002/anie.202210491] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Indexed: 01/11/2023]
Abstract
A new method for regioselective zincations of challenging N-heterocyclic substrates such as pyrimidines and pyridazine was reported using bimetallic bases TMPZnX⋅LiX (TMP=2,2,6,6-tetramethylpiperidyl; X=Cl, Br). Reactions occurred under mild conditions (25-70 °C, using 1.75 equivalents of base without additives), furnishing 2-zincated pyrimidines and 3-zincated pyridazine, which were then trapped with a variety of electrophiles. Contrasting with other s-block metalating systems, which lack selectivity in their reactions even when operating at low temperatures, these mixed Li/Zn bases enabled unprecedented regioselectivities that cannot be replicated by either LiTMP nor Zn(TMP)2 on their own. Spectroscopic and structural interrogations of organometallic intermediates involved in these reactions have shed light on the complex constitution of reaction mixtures and the origins of their special reactivities.
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Affiliation(s)
- Alexander Kremsmair
- Department Chemie & BiochemieLudwig Maximilians-Universität MünchenButenandtstrasse 5–13, Haus F81377MünchenGermany
| | - Alisa S. Sunagatullina
- Department Chemie & BiochemieLudwig Maximilians-Universität MünchenButenandtstrasse 5–13, Haus F81377MünchenGermany
| | - Leonie J. Bole
- Department für Chemie und BiochemieUniversität BernFreiestrasse 33012BernSwitzerland
| | - Pasquale Mastropierro
- Department für Chemie und BiochemieUniversität BernFreiestrasse 33012BernSwitzerland
| | - Simon Graßl
- Department Chemie & BiochemieLudwig Maximilians-Universität MünchenButenandtstrasse 5–13, Haus F81377MünchenGermany
| | - Henrik R. Wilke
- Department Chemie & BiochemieLudwig Maximilians-Universität MünchenButenandtstrasse 5–13, Haus F81377MünchenGermany
| | - Edouard Godineau
- Forschung & Entwicklung SteinSyngenta Crop Protection AGSchaffhauserstrasse 1014332SteinSwitzerland
| | - Eva Hevia
- Department für Chemie und BiochemieUniversität BernFreiestrasse 33012BernSwitzerland
| | - Paul Knochel
- Department Chemie & BiochemieLudwig Maximilians-Universität MünchenButenandtstrasse 5–13, Haus F81377MünchenGermany
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2
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Kremsmair A, Sunagatullina AS, Bole LJ, Mastropierro P, Graßl S, Wilke HR, Godineau E, Hevia E, Knochel P. Exploiting Coordination Effects for the Regioselective Zincation of Diazines Using TMPZnX·LiX (X = Cl, Br). Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202210491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
| | | | - Leonie J. Bole
- Universität Bern: Universitat Bern Department für Chemie und Biochemie SWITZERLAND
| | | | - Simon Graßl
- Ludwig-Maximilians-Universitat Munchen Department of Chemistry GERMANY
| | - Henrik R. Wilke
- Ludwig-Maximilians-Universitat Munchen Department of Chemistry GERMANY
| | - Edouard Godineau
- Syngenta Crop Protection AG Forschung & Entwicklung Stein SWITZERLAND
| | - Eva Hevia
- Universität Bern: Universitat Bern Chemie und Biochemie SWITZERLAND
| | - Paul Knochel
- Ludwig-Maximilians-Universitat Munchen Department of Chemistry Butenandtstr. 5-13 81377 München GERMANY
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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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Kremsmair A, Hess A, Heinz B, Knochel P. Regioselective Magnesiations and Zincations of Aromatics and Heterocycles Triggered by Lewis Acids. Chemistry 2021; 28:e202103269. [PMID: 34704653 PMCID: PMC9300163 DOI: 10.1002/chem.202103269] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Indexed: 11/11/2022]
Abstract
Mixed TMP‐bases (TMP=2,2,6,6‐tetramethylpiperidyl), such as TMPMgCl ⋅ LiCl, TMP2Mg ⋅ 2LiCl, TMPZnCl ⋅ LiCl and TMP2Zn ⋅ 2LiCl, are outstanding reagents for the metalation of functionalized aromatics and heterocycles. In the presence of Lewis acids, such as BF3 ⋅ OEt2 or MgCl2, the metalation scope of such bases was dramatically increased, and regioselectivity switches were achieved in the presence or absence of these Lewis acids. Furthermore, highly reactive lithium bases, such as TMPLi or Cy2NLi, are also compatible with various Lewis acids, such as MgCl2 ⋅ 2LiCl, ZnCl2 ⋅ 2LiCl or CuCN ⋅ 2LiCl. Performing such metalations in continuous flow using commercial setups permitted practical and convenient reaction conditions.
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Affiliation(s)
- Alexander Kremsmair
- Ludwig-Maximilians-Universität München: Ludwig-Maximilians-Universitat Munchen, Chemie und Pharmazie, GERMANY
| | - Andreas Hess
- Ludwig-Maximilians-Universität München: Ludwig-Maximilians-Universitat Munchen, Chemie und Pharmazie, GERMANY
| | - Benjamin Heinz
- Ludwig-Maximilians-Universität München: Ludwig-Maximilians-Universitat Munchen, Chemie und Pharamzie, GERMANY
| | - Paul Knochel
- Ludwig-Maximilians-Universitat Munchen, Department of Chemistry, Butenandtstr. 5-13, 81377, München, GERMANY
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Grams S, Eyselein J, Langer J, Färber C, Harder S. Boosting Low-Valent Aluminum(I) Reactivity with a Potassium Reagent. Angew Chem Int Ed Engl 2020; 59:15982-15986. [PMID: 32449816 PMCID: PMC7540686 DOI: 10.1002/anie.202006693] [Citation(s) in RCA: 90] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Indexed: 12/11/2022]
Abstract
The reagent RK [R=CH(SiMe3 )2 or N(SiMe3 )2 ] was expected to react with the low-valent (DIPP BDI)Al (DIPP BDI=HC[C(Me)N(DIPP)]2 , DIPP=2,6-iPr-phenyl) to give [(DIPP BDI)AlR]- K+ . However, deprotonation of the Me group in the ligand backbone was observed and [H2 C=C(N-DIPP)-C(H)=C(Me)-N-DIPP]Al- K+ (1) crystallized as a bright-yellow product (73 %). Like most anionic AlI complexes, 1 forms a dimer in which formally negatively charged Al centers are bridged by K+ ions, showing strong K+ ⋅⋅⋅DIPP interactions. The rather short Al-K bonds [3.499(1)-3.588(1) Å] indicate tight bonding of the dimer. According to DOSY NMR analysis, 1 is dimeric in C6 H6 and monomeric in THF, but slowly reacts with both solvents. In reaction with C6 H6 , two C-H bond activations are observed and a product with a para-phenylene moiety was exclusively isolated. DFT calculations confirm that the Al center in 1 is more reactive than that in (DIPP BDI)Al. Calculations show that both AlI and K+ work in concert and determines the reactivity of 1.
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Affiliation(s)
- Samuel Grams
- Chair of Inorganic and Organometallic ChemistryUniversität Erlangen-NürnbergEgerlandstrasse 191058ErlangenGermany
| | - Jonathan Eyselein
- Chair of Inorganic and Organometallic ChemistryUniversität Erlangen-NürnbergEgerlandstrasse 191058ErlangenGermany
| | - Jens Langer
- Chair of Inorganic and Organometallic ChemistryUniversität Erlangen-NürnbergEgerlandstrasse 191058ErlangenGermany
| | - Christian Färber
- Chair of Inorganic and Organometallic ChemistryUniversität Erlangen-NürnbergEgerlandstrasse 191058ErlangenGermany
| | - Sjoerd Harder
- Chair of Inorganic and Organometallic ChemistryUniversität Erlangen-NürnbergEgerlandstrasse 191058ErlangenGermany
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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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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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Grams S, Eyselein J, Langer J, Färber C, Harder S. Boosting Low‐Valent Aluminum(I) Reactivity with a Potassium Reagent. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202006693] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Samuel Grams
- Chair of Inorganic and Organometallic Chemistry Universität Erlangen-Nürnberg Egerlandstrasse 1 91058 Erlangen Germany
| | - Jonathan Eyselein
- Chair of Inorganic and Organometallic Chemistry Universität Erlangen-Nürnberg Egerlandstrasse 1 91058 Erlangen Germany
| | - Jens Langer
- Chair of Inorganic and Organometallic Chemistry Universität Erlangen-Nürnberg Egerlandstrasse 1 91058 Erlangen Germany
| | - Christian Färber
- Chair of Inorganic and Organometallic Chemistry Universität Erlangen-Nürnberg Egerlandstrasse 1 91058 Erlangen Germany
| | - Sjoerd Harder
- Chair of Inorganic and Organometallic Chemistry Universität Erlangen-Nürnberg Egerlandstrasse 1 91058 Erlangen Germany
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Varga S, Angyal P, Martin G, Egyed O, Holczbauer T, Soós T. Total Syntheses of (−)‐Minovincine and (−)‐Aspidofractinine through a Sequence of Cascade Reactions. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202004769] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Szilárd Varga
- Institute of Organic Chemistry Research Centre for Natural Sciences 2 Magyar tudósok krt. 1117 Budapest Hungary
| | - Péter Angyal
- Institute of Organic Chemistry Research Centre for Natural Sciences 2 Magyar tudósok krt. 1117 Budapest Hungary
| | - Gábor Martin
- Institute of Organic Chemistry Research Centre for Natural Sciences 2 Magyar tudósok krt. 1117 Budapest Hungary
| | - Orsolya Egyed
- Instrumentation Center Research Centre for Natural Sciences 2 Magyar tudósok krt. 1117 Budapest Hungary
| | - Tamás Holczbauer
- Institute of Organic Chemistry Research Centre for Natural Sciences 2 Magyar tudósok krt. 1117 Budapest Hungary
- Instrumentation Center Research Centre for Natural Sciences 2 Magyar tudósok krt. 1117 Budapest Hungary
| | - Tibor Soós
- Institute of Organic Chemistry Research Centre for Natural Sciences 2 Magyar tudósok krt. 1117 Budapest Hungary
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Varga S, Angyal P, Martin G, Egyed O, Holczbauer T, Soós T. Total Syntheses of (-)-Minovincine and (-)-Aspidofractinine through a Sequence of Cascade Reactions. Angew Chem Int Ed Engl 2020; 59:13547-13551. [PMID: 32351014 PMCID: PMC7497198 DOI: 10.1002/anie.202004769] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 04/27/2020] [Indexed: 12/31/2022]
Abstract
We report 8‐step syntheses of (−)‐minovincine and (−)‐aspidofractinine using easily available and inexpensive reagents and catalyst. A key element of the strategy was the utilization of a sequence of cascade reactions to rapidly construct the penta‐ and hexacyclic frameworks. These cascade transformations included organocatalytic Michael‐aldol condensation, a multistep anionic Michael‐SN2 cascade reaction, and Mannich reaction interrupted Fischer indolization. To streamline the synthetic routes, we also investigated the deliberate use of steric effect to secure various chemo‐ and regioselective transformations.
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Affiliation(s)
- Szilárd Varga
- Institute of Organic Chemistry, Research Centre for Natural Sciences, 2 Magyar tudósok krt., 1117, Budapest, Hungary
| | - Péter Angyal
- Institute of Organic Chemistry, Research Centre for Natural Sciences, 2 Magyar tudósok krt., 1117, Budapest, Hungary
| | - Gábor Martin
- Institute of Organic Chemistry, Research Centre for Natural Sciences, 2 Magyar tudósok krt., 1117, Budapest, Hungary
| | - Orsolya Egyed
- Instrumentation Center, Research Centre for Natural Sciences, 2 Magyar tudósok krt., 1117, Budapest, Hungary
| | - Tamás Holczbauer
- Institute of Organic Chemistry, Research Centre for Natural Sciences, 2 Magyar tudósok krt., 1117, Budapest, Hungary.,Instrumentation Center, Research Centre for Natural Sciences, 2 Magyar tudósok krt., 1117, Budapest, Hungary
| | - Tibor Soós
- Institute of Organic Chemistry, Research Centre for Natural Sciences, 2 Magyar tudósok krt., 1117, Budapest, Hungary
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Abstract
For the preparation of zinc organometallics bearing highly sensitive functional groups such as ketones, aldehydes or nitro groups, especially mild halogen-zinc exchange reagents have proven to be of great potential. In this Minireview, the latest research in the area of the halogen-zinc exchange reaction is reported, with a special focus lying on novel dialkylzinc reagents complexed with lithium alkoxides. Additionally, the preparation and application of organofluorine zinc reagents and transition-metal-catalyzed halogen-zinc exchange reactions are reviewed.
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Affiliation(s)
- Moritz Balkenhohl
- Department Chemie und PharmazieLudwig-Maximilians-Universität MünchenButenandtstrasse 5–13, Haus F81377MünchenGermany
| | - Paul Knochel
- Department Chemie und PharmazieLudwig-Maximilians-Universität MünchenButenandtstrasse 5–13, Haus F81377MünchenGermany
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