1
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He H, Yan J, Jin J, Yan Z, Yan Q, Wang W, Jiang H, Wang H, Chen F. TfOH-catalyzed regioselective N2-alkylation of indazoles with diazo compounds. Chem Commun (Camb) 2022; 58:6429-6432. [PMID: 35546320 DOI: 10.1039/d2cc01404a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Selective alkylation of indazoles is still a highly challenging topic in chemistry and the synthesis of important molecules. Herein, a novel highly selective N2-alkylation of indazoles with diazo compounds is described in the presence of TfOH. Unlike the traditional metal- and base-catalysed version, this protocol highlights the regioselectivity of alkylation of indazoles and a metal-free catalysis system, affording N2-alkylated products in good to excellent yields with high regioselectivity (N2/N1 up to 100/0) and excellent functional group tolerance. Furthermore, a gram scale synthesis was conducted successfully to give rise to the corresponding products. Mechanistic studies through control experiments provide plausible mechanistic proposals.
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Affiliation(s)
- Hangli He
- Pharmaceutical Research Institute, Wuhan Institute of Technology, Wuhan 430205, China. .,School of Chemical Engineering & Pharmacy, Wuhan Institute of Technology, Wuhan 430205, China
| | - Jingyu Yan
- School of Chemical Engineering & Pharmacy, Wuhan Institute of Technology, Wuhan 430205, China
| | - Jingru Jin
- Pharmaceutical Research Institute, Wuhan Institute of Technology, Wuhan 430205, China. .,School of Chemical Engineering & Pharmacy, Wuhan Institute of Technology, Wuhan 430205, China
| | - Zhewei Yan
- Pharmaceutical Research Institute, Wuhan Institute of Technology, Wuhan 430205, China. .,School of Chemical Engineering & Pharmacy, Wuhan Institute of Technology, Wuhan 430205, China
| | - Qiongjiao Yan
- Pharmaceutical Research Institute, Wuhan Institute of Technology, Wuhan 430205, China.
| | - Wei Wang
- Pharmaceutical Research Institute, Wuhan Institute of Technology, Wuhan 430205, China.
| | - Haipeng Jiang
- Pharmaceutical Research Institute, Wuhan Institute of Technology, Wuhan 430205, China.
| | - Haifeng Wang
- Pharmaceutical Research Institute, Wuhan Institute of Technology, Wuhan 430205, China. .,School of Chemical Engineering & Pharmacy, Wuhan Institute of Technology, Wuhan 430205, China
| | - Fener Chen
- Pharmaceutical Research Institute, Wuhan Institute of Technology, Wuhan 430205, China. .,Engineering Center of Catalysis and Synthesis for Chiral Molecules, Department of Chemistry, Fudan University, Shanghai 200433, China. .,Shanghai Engineering Center of Industrial Catalysis for Chiral Drugs, Shanghai 200433, China
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2
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Chen SJ, Golden DL, Krska SW, Stahl SS. Copper-Catalyzed Cross-Coupling of Benzylic C-H Bonds and Azoles with Controlled N-Site Selectivity. J Am Chem Soc 2021; 143:14438-14444. [PMID: 34464528 PMCID: PMC8487258 DOI: 10.1021/jacs.1c07117] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Azoles are important motifs in medicinal chemistry, and elaboration of their structures via direct N-H/C-H coupling could have broad utility in drug discovery. The ambident reactivity of many azoles, however, presents significant selectivity challenges. Here, we report a copper-catalyzed method that achieves site-selective cross-coupling of pyrazoles and other N-H heterocycles with substrates bearing (hetero)benzylic C-H bonds. Excellent N-site selectivity is achieved, with the preferred site controlled by the identity of co-catalytic additives. This cross-coupling strategy features broad scope for both the N-H heterocycle and benzylic C-H coupling partners, enabling application of this method to complex molecule synthesis and medicinal chemistry.
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Affiliation(s)
- Si-Jie Chen
- Department of Chemistry, University of Wisconsin–Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Dung L. Golden
- Department of Chemistry, University of Wisconsin–Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Shane W. Krska
- High-Throughput Experimentation and Lead Discovery Capabilities, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Shannon S. Stahl
- Department of Chemistry, University of Wisconsin–Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
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3
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Alam RM, Keating JJ. Regioselective N-alkylation of the 1 H-indazole scaffold; ring substituent and N-alkylating reagent effects on regioisomeric distribution. Beilstein J Org Chem 2021; 17:1939-1951. [PMID: 34386104 PMCID: PMC8353588 DOI: 10.3762/bjoc.17.127] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 07/23/2021] [Indexed: 11/23/2022] Open
Abstract
The indazole scaffold represents a promising pharmacophore, commonly incorporated in a variety of therapeutic drugs. Although indazole-containing drugs are frequently marketed as the corresponding N-alkyl 1H- or 2H-indazole derivative, the efficient synthesis and isolation of the desired N-1 or N-2 alkylindazole regioisomer can often be challenging and adversely affect product yield. Thus, as part of a broader study focusing on the synthesis of bioactive indazole derivatives, we aimed to develop a regioselective protocol for the synthesis of N-1 alkylindazoles. Initial screening of various conditions revealed that the combination of sodium hydride (NaH) in tetrahydrofuran (THF) (in the presence of an alkyl bromide), represented a promising system for N-1 selective indazole alkylation. For example, among fourteen C-3 substituted indazoles examined, we observed > 99% N-1 regioselectivity for 3-carboxymethyl, 3-tert-butyl, 3-COMe, and 3-carboxamide indazoles. Further extension of this optimized (NaH in THF) protocol to various C-3, -4, -5, -6, and -7 substituted indazoles has highlighted the impact of steric and electronic effects on N-1/N-2 regioisomeric distribution. For example, employing C-7 NO2 or CO2Me substituted indazoles conferred excellent N-2 regioselectivity (≥ 96%). Importantly, we show that this optimized N-alkylation procedure tolerates a wide structural variety of alkylating reagents, including primary alkyl halide and secondary alkyl tosylate electrophiles, while maintaining a high degree of N-1 regioselectivity.
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Affiliation(s)
- Ryan M Alam
- Analytical and Biological Chemistry Research Facility (ABCRF), University College Cork, College Road, Cork, T12 YN60, Ireland
- School of Chemistry, Kane Building, University College Cork, T12 YN60, Ireland
| | - John J Keating
- Analytical and Biological Chemistry Research Facility (ABCRF), University College Cork, College Road, Cork, T12 YN60, Ireland
- School of Chemistry, Kane Building, University College Cork, T12 YN60, Ireland
- School of Pharmacy, Pharmacy Building, University College Cork, T12 YN60, Ireland
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4
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Rh(III)-catalyzed annulation of azobenzenes and α-Cl ketones toward 3-acyl-2H-indazoles. CHINESE CHEM LETT 2021. [DOI: 10.1016/j.cclet.2020.12.027] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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5
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Solomin VV, Seins A, Jirgensons A. Synthesis of indazoles from 2-formylphenylboronic acids. RSC Adv 2021; 11:22710-22714. [PMID: 35480464 PMCID: PMC9034367 DOI: 10.1039/d1ra04056a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Accepted: 06/22/2021] [Indexed: 11/21/2022] Open
Abstract
A method for the synthesis of indazoles was developed which involves a copper(ii) acetate catalysed reaction of 2-formylboronic acids with diazadicaboxylates followed by acid or base induced ring closure.
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Affiliation(s)
- Vitalii V. Solomin
- Latvian Institute of Organic Synthesis
- Riga
- Latvia
- Faculty of Materials Science and Applied Chemistry
- Riga Technical University
| | - Alberts Seins
- Latvian Institute of Organic Synthesis
- Riga
- Latvia
- Faculty of Materials Science and Applied Chemistry
- Riga Technical University
| | - Aigars Jirgensons
- Latvian Institute of Organic Synthesis
- Riga
- Latvia
- Faculty of Materials Science and Applied Chemistry
- Riga Technical University
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6
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Ghosh S, Mondal S, Hajra A. Direct Catalytic Functionalization of Indazole Derivatives. Adv Synth Catal 2020. [DOI: 10.1002/adsc.202000423] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Sumit Ghosh
- Department of Chemistry Visva-Bharati (A Central University) Santiniketan 731235 India
| | - Susmita Mondal
- Department of Chemistry Visva-Bharati (A Central University) Santiniketan 731235 India
| | - Alakananda Hajra
- Department of Chemistry Visva-Bharati (A Central University) Santiniketan 731235 India
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7
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Ye Y, Kevlishvili I, Feng S, Liu P, Buchwald SL. Highly Enantioselective Synthesis of Indazoles with a C3-Quaternary Chiral Center Using CuH Catalysis. J Am Chem Soc 2020; 142:10550-10556. [PMID: 32408745 DOI: 10.1021/jacs.0c04286] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
C3-substituted 1H-indazoles are useful and important substructures in many pharmaceuticals. Methods for direct C3-functionalization of indazoles are relatively rare, compared to reactions developed for the more nucleophilic N1 and N2 positions. Herein, we report a highly C3-selective allylation reaction of 1H-N-(benzoyloxy)indazoles using CuH catalysis. A variety of C3-allyl 1H-indazoles with quaternary stereocenters were efficiently prepared with high levels of enantioselectivity. Density functional theory (DFT) calculations were performed to explain the reactivity differences between indazole and indole electrophiles, the latter of which was used in our previously reported method. The calculations suggest that the indazole allylation reaction proceeds through an enantioselectivity-determining six-membered Zimmerman-Traxler-type transition state, rather than an oxidative addition/reductive elimination sequence, as we proposed in the case of indole alkylation. The enantioselectivity of the reaction is governed by both ligand-substrate steric interactions and steric repulsions involving the pseudoaxial substituent in the six-membered allylation transition state.
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Affiliation(s)
- Yuxuan Ye
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Ilia Kevlishvili
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Sheng Feng
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Peng Liu
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Stephen L Buchwald
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
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8
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Raut S, Tidke A, Dhotre B, Arif PM. Different Strategies to the Synthesis of Indazole and its Derivatives: A Review. MINI-REV ORG CHEM 2020. [DOI: 10.2174/1570193x16666190430160324] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In this review, works of various researchers working on the synthesis of indazole and their related compound are cited. The review comprises of methodologies for the synthesis of 1H and 2H indazole derivatives, along with some pharmacological activities. In this review, research papers published in various peer-reviewed journals between the year 2000 and year 2017 are enlisted in alphabetical order.
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Affiliation(s)
- Santosh Raut
- Maulana Azad College and Research Center, Rouza Bagh, Aurangabad (M.S.), India
| | - Atul Tidke
- Maulana Azad College and Research Center, Rouza Bagh, Aurangabad (M.S.), India
| | | | - Pathan Mohd Arif
- Maulana Azad College and Research Center, Rouza Bagh, Aurangabad (M.S.), India
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9
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Dissanayake DMMM, Vannucci AK. Selective N1-Acylation of Indazoles with Acid Anhydrides Using an Electrochemical Approach. Org Lett 2019; 21:457-460. [PMID: 30624070 DOI: 10.1021/acs.orglett.8b03683] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
An electrochemical synthesis method for the selective N1-acylation of indazoles has been developed. This "anion pool" approach electrochemically reduces indazole molecules generating indazole anions and H2. Acid anhydrides are then introduced to the solution resulting in selective acylation of the N1-position of the indazoles. This procedure can also be applied to the acylation of benzimidazoles and indoles. The reaction can also be performed using a 9 V battery without loss of reaction efficiency.
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Affiliation(s)
- D M M Mevan Dissanayake
- Department of Chemistry and Biochemistry , University of South Carolina , 541 Main Street, Columbia , South Carolina 29208 , United States
| | - Aaron K Vannucci
- Department of Chemistry and Biochemistry , University of South Carolina , 541 Main Street, Columbia , South Carolina 29208 , United States
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10
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Schoene J, Bel Abed H, Schmieder P, Christmann M, Nazaré M. A General One-Pot Synthesis of 2H-Indazoles Using an Organophosphorus-Silane System. Chemistry 2018; 24:9090-9100. [PMID: 29644761 DOI: 10.1002/chem.201800763] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Indexed: 11/11/2022]
Abstract
A simple and direct approach for the regioselective construction of the privileged 2H-indazole scaffold is described. The developed one-pot strategy involves phospholene-mediated N-N bond formation to access 2H-indazoles. The amount of organophosphorus reagent was minimized by recycling the phospholene oxide with organosilane reductants. Starting from functionalized 2-nitrobenzaldehydes and primary amines, a mild reductive cyclization, involving the use of commercially available phospholene oxide and silanes, delivered a wide variety of substituted 2H-indazoles in good to excellent yields.
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Affiliation(s)
- Jens Schoene
- Departments of Chemical Biology and Structural Biology, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Campus Berlin-Buch, Robert-Roessle-Str. 10, 13125, Berlin, Germany
| | - Hassen Bel Abed
- Departments of Chemical Biology and Structural Biology, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Campus Berlin-Buch, Robert-Roessle-Str. 10, 13125, Berlin, Germany
| | - Peter Schmieder
- Departments of Chemical Biology and Structural Biology, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Campus Berlin-Buch, Robert-Roessle-Str. 10, 13125, Berlin, Germany
| | - Mathias Christmann
- Institut für Chemie und Biochemie, Organische Chemie, Freie Universität Berlin, Takustrasse. 3, 14195, Berlin, Germany
| | - Marc Nazaré
- Departments of Chemical Biology and Structural Biology, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Campus Berlin-Buch, Robert-Roessle-Str. 10, 13125, Berlin, Germany.,Berlin Institute of Health (BIH), Anna-Louisa-Karsch-Str. 2, 10178 Kapelle-Ufer 2, 10117, Berlin, Germany
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11
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Faarasse S, El Kazzouli S, Naas M, Jouha J, Suzenet F, Guillaumet G. “On Water” Direct C-3 Arylation of 2H-Pyrazolo[3,4-b]pyridines. J Org Chem 2017; 82:12300-12306. [DOI: 10.1021/acs.joc.7b02136] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Soukaina Faarasse
- Euromed
Faculty of Engineering, Euromed University of Fes (UEMF), Route
de Meknès, 30000 Fès, Morocco
- Institut
de Chimie Organique et Analytique (ICOA), Université d’Orléans, UMR CNRS, 7311 BP 6759, 45067 Orléans Cedex 2, France
| | - Saïd El Kazzouli
- Euromed
Faculty of Engineering, Euromed University of Fes (UEMF), Route
de Meknès, 30000 Fès, Morocco
| | - Mohammed Naas
- Institut
de Chimie Organique et Analytique (ICOA), Université d’Orléans, UMR CNRS, 7311 BP 6759, 45067 Orléans Cedex 2, France
| | - Jabrane Jouha
- Institut
de Chimie Organique et Analytique (ICOA), Université d’Orléans, UMR CNRS, 7311 BP 6759, 45067 Orléans Cedex 2, France
| | - Franck Suzenet
- Institut
de Chimie Organique et Analytique (ICOA), Université d’Orléans, UMR CNRS, 7311 BP 6759, 45067 Orléans Cedex 2, France
| | - Gérald Guillaumet
- Institut
de Chimie Organique et Analytique (ICOA), Université d’Orléans, UMR CNRS, 7311 BP 6759, 45067 Orléans Cedex 2, France
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12
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Long Z, Wang Z, Zhou D, Wan D, You J. Rh(III)-Catalyzed Regio- and Chemoselective [4 + 1]-Annulation of Azoxy Compounds with Diazoesters for the Synthesis of 2H-Indazoles: Roles of the Azoxy Oxygen Atom. Org Lett 2017; 19:2777-2780. [PMID: 28514173 DOI: 10.1021/acs.orglett.7b00631] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A Rh(III)-catalyzed tandem C-H alkylation/intramolecular decarboxylative cyclization of azoxy compounds with diazoesters for the synthesis of 3-acyl-2H-indazoles is disclosed. The azoxy instead of the azo group enables a distinct approach for cyclative capture, leading to a [4 + 1]-annulation rather than a classic [4 + 2] manner. The azoxy oxygen atom is traceless after annulation, and further removal from the product is not required. This reaction features a complete regioselectivity for unsymmetrical azoxybenzenes and a compatibility of monoaryldiazene oxides.
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Affiliation(s)
- Zhen Long
- Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, Sichuan University , 29 Wangjiang Road, Chengdu 610064, P.R. China
| | - Zhigang Wang
- Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, Sichuan University , 29 Wangjiang Road, Chengdu 610064, P.R. China
| | - Danni Zhou
- Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, Sichuan University , 29 Wangjiang Road, Chengdu 610064, P.R. China
| | - Danyang Wan
- Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, Sichuan University , 29 Wangjiang Road, Chengdu 610064, P.R. China
| | - Jingsong You
- Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, Sichuan University , 29 Wangjiang Road, Chengdu 610064, P.R. China
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13
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Zhang XL, Ma Y, Pan Q, Bai ZG, Qi H, Zhang QZ. Synthesis of (5,6-Dihydro-4H-pyrrolo[1,2-b]pyrazol-3-yl)-methanamine. HETEROCYCLES 2017. [DOI: 10.3987/com-17-13772] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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14
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Degnan AP, Tora GO, Huang H, Conlon DA, Davis CD, Hanumegowda UM, Hou X, Hsiao Y, Hu J, Krause R, Li YW, Newton AE, Pieschl RL, Raybon J, Rosner T, Sun JH, Taber MT, Taylor SJ, Wong MK, Zhang H, Lodge NJ, Bronson JJ, Macor JE, Gillman KW. Discovery of Indazoles as Potent, Orally Active Dual Neurokinin 1 Receptor Antagonists and Serotonin Transporter Inhibitors for the Treatment of Depression. ACS Chem Neurosci 2016; 7:1635-1640. [PMID: 27744678 DOI: 10.1021/acschemneuro.6b00337] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Combination studies of neurokinin 1 (NK1) receptor antagonists and serotonin-selective reuptake inhibitors (SSRIs) have shown promise in preclinical models of depression. Such a combination may offer important advantages over the current standard of care. Herein we describe the discovery and optimization of an indazole-based chemotype to provide a series of potent dual NK1 receptor antagonists/serotonin transporter (SERT) inhibitors to overcome issues of ion channel blockade. This effort culminated in the identification of compound 9, an analogue that demonstrated favorable oral bioavailability, excellent brain uptake, and robust in vivo efficacy in a validated depression model. Over the course of this work, a novel heterocycle-directed asymmetric hydrogenation was developed to facilitate installation of the key stereogenic center.
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Affiliation(s)
- Andrew P. Degnan
- Research and Development, Bristol-Myers Squibb Company, Wallingford, Connecticut 06492, United States
| | - George O. Tora
- Research and Development, Bristol-Myers Squibb Company, Wallingford, Connecticut 06492, United States
| | - Hong Huang
- Research and Development, Bristol-Myers Squibb Company, Wallingford, Connecticut 06492, United States
| | - David A. Conlon
- Chemical
Development, Bristol-Myers Squibb Company, New Brunswick, New Jersey 08903, United States
| | - Carl D. Davis
- Research and Development, Bristol-Myers Squibb Company, Wallingford, Connecticut 06492, United States
| | - Umesh M. Hanumegowda
- Research and Development, Bristol-Myers Squibb Company, Wallingford, Connecticut 06492, United States
| | - Xiaoping Hou
- Department of Chemical Synthesis, Bristol-Myers Squibb Company, Princeton, New Jersey 08543, United States
| | - Yi Hsiao
- Chemical
Development, Bristol-Myers Squibb Company, New Brunswick, New Jersey 08903, United States
| | - Joanna Hu
- Research and Development, Bristol-Myers Squibb Company, Wallingford, Connecticut 06492, United States
| | - Rudolph Krause
- Research and Development, Bristol-Myers Squibb Company, Wallingford, Connecticut 06492, United States
| | - Yu-Wen Li
- Research and Development, Bristol-Myers Squibb Company, Wallingford, Connecticut 06492, United States
| | - Amy E. Newton
- Research and Development, Bristol-Myers Squibb Company, Wallingford, Connecticut 06492, United States
| | - Rick L. Pieschl
- Research and Development, Bristol-Myers Squibb Company, Wallingford, Connecticut 06492, United States
| | - Joseph Raybon
- Research and Development, Bristol-Myers Squibb Company, Wallingford, Connecticut 06492, United States
| | - Thorsten Rosner
- Chemical
Development, Bristol-Myers Squibb Company, New Brunswick, New Jersey 08903, United States
| | - Jung-Hui Sun
- Department of Chemical Synthesis, Bristol-Myers Squibb Company, Princeton, New Jersey 08543, United States
| | - Matthew T. Taber
- Research and Development, Bristol-Myers Squibb Company, Wallingford, Connecticut 06492, United States
| | - Sarah J. Taylor
- Research and Development, Bristol-Myers Squibb Company, Wallingford, Connecticut 06492, United States
| | - Michael K. Wong
- Department of Chemical Synthesis, Bristol-Myers Squibb Company, Princeton, New Jersey 08543, United States
| | - Huiping Zhang
- Department of Chemical Synthesis, Bristol-Myers Squibb Company, Princeton, New Jersey 08543, United States
| | - Nicholas J. Lodge
- Research and Development, Bristol-Myers Squibb Company, Wallingford, Connecticut 06492, United States
| | - Joanne J. Bronson
- Research and Development, Bristol-Myers Squibb Company, Wallingford, Connecticut 06492, United States
| | - John E. Macor
- Research and Development, Bristol-Myers Squibb Company, Wallingford, Connecticut 06492, United States
| | - Kevin W. Gillman
- Research and Development, Bristol-Myers Squibb Company, Wallingford, Connecticut 06492, United States
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15
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Bel Abed H, Schoene J, Christmann M, Nazaré M. Organophosphorus-mediated N-N bond formation: facile access to 3-amino-2H-indazoles. Org Biomol Chem 2016; 14:8520-8. [PMID: 27541713 DOI: 10.1039/c6ob01544a] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A convenient and efficient strategy has been devised to access 3-amino-2H-indazole derivatives in two steps from readily available starting materials. The conversion of 2-nitrobenzonitriles to substituted benzamidines followed by an organophosphorus-mediated reductive cyclization and a subsequent N-N bond formation afforded 3-amino-2H-indazoles in good to excellent yields.
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Affiliation(s)
- Hassen Bel Abed
- Leibniz-Institut für Molekulare Pharmakologie (FMP), Campus Berlin-Buch, Robert-Roessle-Str. 10, 13125 Berlin, Germany.
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16
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Basu K, Poirier M, Ruck RT. Solution to the C3–Arylation of Indazoles: Development of a Scalable Method. Org Lett 2016; 18:3218-21. [DOI: 10.1021/acs.orglett.6b01456] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Kallol Basu
- Department of Process & Analytical Chemistry, Merck Research Laboratories, Rahway, New Jersey 07065, United States
| | - Marc Poirier
- Department of Process & Analytical Chemistry, Merck Research Laboratories, Rahway, New Jersey 07065, United States
| | - Rebecca T. Ruck
- Department of Process & Analytical Chemistry, Merck Research Laboratories, Rahway, New Jersey 07065, United States
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17
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Rossi R, Lessi M, Manzini C, Marianetti G, Bellina F. Achievement of regioselectivity in transition metal-catalyzed direct C–H (hetero)arylation reactions of heteroarenes with one heteroatom through the use of removable protecting/blocking substituents or traceless directing groups. Tetrahedron 2016. [DOI: 10.1016/j.tet.2016.02.037] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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18
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Jeong T, Han SH, Han S, Sharma S, Park J, Lee JS, Kwak JH, Jung YH, Kim IS. Access to 3-Acyl-(2H)-indazoles via Rh(III)-Catalyzed C–H Addition and Cyclization of Azobenzenes with α-Keto Aldehydes. Org Lett 2016; 18:232-5. [DOI: 10.1021/acs.orglett.5b03368] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Taejoo Jeong
- School
of Pharmacy, Sungkyunkwan University, Suwon 440-746, Republic of Korea
| | - Sang Hoon Han
- School
of Pharmacy, Sungkyunkwan University, Suwon 440-746, Republic of Korea
| | - Sangil Han
- School
of Pharmacy, Sungkyunkwan University, Suwon 440-746, Republic of Korea
| | - Satyasheel Sharma
- School
of Pharmacy, Sungkyunkwan University, Suwon 440-746, Republic of Korea
| | - Jihye Park
- School
of Pharmacy, Sungkyunkwan University, Suwon 440-746, Republic of Korea
| | - Jong Suk Lee
- Biocenter, Gyeonggi Institute of Science & Technology Promotion, Suwon 443-270, Republic of Korea
| | - Jong Hwan Kwak
- School
of Pharmacy, Sungkyunkwan University, Suwon 440-746, Republic of Korea
| | - Young Hoon Jung
- School
of Pharmacy, Sungkyunkwan University, Suwon 440-746, Republic of Korea
| | - In Su Kim
- School
of Pharmacy, Sungkyunkwan University, Suwon 440-746, Republic of Korea
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19
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Nguyen TM, Manohar N, Nicewicz DA. anti-Markovnikov hydroamination of alkenes catalyzed by a two-component organic photoredox system: direct access to phenethylamine derivatives. Angew Chem Int Ed Engl 2014; 53:6198-201. [PMID: 24764195 PMCID: PMC4073672 DOI: 10.1002/anie.201402443] [Citation(s) in RCA: 194] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Revised: 03/25/2014] [Indexed: 11/09/2022]
Abstract
Disclosed herein is a general catalytic system for the intermolecular anti-Markovnikov hydroamination of alkenes. By using an organocatalytic photoredox system, α- and β-substituted styrenes as well as aliphatic alkenes undergo anti-Markovnikov hydroamination. Heterocyclic amines were also successfully employed as nitrogen nucleophiles, thus providing a direct route to heterocyclic motifs common in medicinal agents.
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Affiliation(s)
- Tien M. Nguyen
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-3290 (USA)
| | - Namita Manohar
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-3290 (USA)
| | - David A. Nicewicz
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-3290 (USA)
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20
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Nguyen TM, Manohar N, Nicewicz DA. anti-Markovnikov Hydroamination of Alkenes Catalyzed by a Two-Component Organic Photoredox System: Direct Access to Phenethylamine Derivatives. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201402443] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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21
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Meng Z, Sun B, Reddy PA, Siddiqui MA. Acid-mediated cyclizations of SEM-protected heterocyclic anilines and adjacent hydroxyls or enol-ethers. Tetrahedron Lett 2013. [DOI: 10.1016/j.tetlet.2013.09.059] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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22
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Tora G, Degnan AP, Conway CM, Kostich WA, Davis CD, Pin SS, Schartman R, Xu C, Widmann KA, Macor JE, Dubowchik GM. Preparation of imidazoles as potent calcitonin gene-related peptide (CGRP) antagonists. Bioorg Med Chem Lett 2013; 23:5684-8. [PMID: 23993336 DOI: 10.1016/j.bmcl.2013.08.031] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Revised: 07/26/2013] [Accepted: 08/05/2013] [Indexed: 11/17/2022]
Abstract
Several new potent CGRP receptor antagonists have been prepared in which the amide bond of lead compound 1 has been replaced by bioisosteric imidazole moieties. Substitution at N-1 of the imidazole was optimized to afford compounds with comparable potency to that of lead 1. Conformational restraint of the imidazole to form tetrahydroimidazo[1,5-a]pyrazine 43 gave substantially improved permeability.
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Affiliation(s)
- George Tora
- Medicinal Chemistry, Molecular Sciences and Candidate Optimization, Bristol-Myers Squibb, 311 Pennington-Rocky Hill Road, Pennington, NJ 08534, USA.
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23
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Facile and efficient syntheses of a series of N-benzyl and N-biphenylmethyl substituted imidazole derivatives based on (E)-urocanic acid, as angiotensin II AT1 receptor blockers. Molecules 2013; 18:7510-32. [PMID: 23807577 PMCID: PMC6270370 DOI: 10.3390/molecules18077510] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Revised: 06/17/2013] [Accepted: 06/20/2013] [Indexed: 11/16/2022] Open
Abstract
In the present work, a facile and efficient route for the synthesis of a series of N-substituted imidazole derivatives is described. Docking studies have revealed that N-substituted imidazole derivatives based on (E)-urocanic acid may be potential antihypertensive leads. Therefore, new AT1 receptor blockers bearing either the benzyl or the biphenylmethyl moiety at the N-1 or N-3 position, either the (E)-acrylate or the propanoate fragment and their related acids at the C-4 position as well as a halogen atom at the C-5 position of the imidazole ring, were synthesized. The newly synthesized analogues were evaluated for binding to human AT1 receptor. The biological results showed that this class of molecules possesses moderate or no activity, thus not always confirming high docking scores. Nonetheless, important conclusions can be derived for their molecular basis of their mode of action and help medicinal chemists to design and synthesize more potent ones. An aliphatic group as in losartan seems to be important for enhancing binding affinity and activity.
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24
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25
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Hattori K, Yamaguchi K, Yamaguchi J, Itami K. Pd- and Cu-catalyzed C–H arylation of indazoles. Tetrahedron 2012. [DOI: 10.1016/j.tet.2012.05.091] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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26
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Agelis G, Resvani A, Durdagi S, Spyridaki K, Tůmová T, Slaninová J, Giannopoulos P, Vlahakos D, Liapakis G, Mavromoustakos T, Matsoukas J. The discovery of new potent non-peptide Angiotensin II AT1 receptor blockers: a concise synthesis, molecular docking studies and biological evaluation of N-substituted 5-butylimidazole derivatives. Eur J Med Chem 2012; 55:358-74. [PMID: 22889560 DOI: 10.1016/j.ejmech.2012.07.040] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2012] [Revised: 07/19/2012] [Accepted: 07/20/2012] [Indexed: 02/07/2023]
Abstract
A convenient and facile synthesis, in silico docking studies and in vitro biological evaluation of N-substituted 5-butylimidazole derivatives as potent Angiotensin II (ANG II) receptor type 1 (AT1) blockers (ARBs) has been reported in the current study. Our efforts have been directed towards the development of an efficient synthetic route allowing the facile introduction of substituents on the imidazole ring. In particular, a series of imidazole based compounds bearing the biphenyl moiety at the N - 1 position, a halogen atom at the C-4 and polar substituents such as hydroxymethyl, aldo or carboxy group at the C-2 position were designed and synthesized. These compounds were evaluated for binding to human AT1 receptor and for ANG II antagonism in vitro on isolated rat uterus. Among them, 5-butyl-1-[[2'-(2H-tetrazol-5-yl)biphenyl-4-yl]methyl]imidazole-2-carboxylic acid (30) exhibited higher binding affinity compared to the other analogues tested (-log IC(50) = 8.46). The latter analogue was also found to be the most active in the rat uterotonic test (pA(2) = 7.83). Importantly, the binding affinity was higher to that of losartan (-log IC(50) = 8.25) indicating the importance of carboxy group at the C-2 position. Experimental findings are in good agreement with docking studies, which were undertaken in order to investigate ligand/AT1 receptor interactions.
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Affiliation(s)
- George Agelis
- Department of Chemistry, University of Patras, Patras 26500, Greece.
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27
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Luo G, Chen L, Pin SS, Xu C, Conway CM, Macor JE, Dubowchik GM. Calcitonin gene-related peptide (CGRP) receptor antagonists: Novel aspartates and succinates. Bioorg Med Chem Lett 2012; 22:2912-6. [DOI: 10.1016/j.bmcl.2012.02.066] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Revised: 02/16/2012] [Accepted: 02/17/2012] [Indexed: 11/26/2022]
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28
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Luo G, Chen L, Civiello R, Pin SS, Xu C, Kostich W, Kelley M, Conway CM, Macor JE, Dubowchik GM. Calcitonin gene-related peptide (CGRP) receptor antagonists: Pyridine as a replacement for a core amide group. Bioorg Med Chem Lett 2012; 22:2917-21. [DOI: 10.1016/j.bmcl.2012.02.065] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Revised: 02/16/2012] [Accepted: 02/17/2012] [Indexed: 10/28/2022]
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29
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30
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Unsinn A, Knochel P. Regioselective zincation of indazoles using TMP2Zn and Negishi cross-coupling with aryl and heteroaryl iodides. Chem Commun (Camb) 2012; 48:2680-2. [DOI: 10.1039/c2cc17804d] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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31
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Arthuis M, Pontikis R, Chabot GG, Seguin J, Quentin L, Bourg S, Morin-Allory L, Florent JC. Synthesis and Structure-Activity Relationships of Constrained Heterocyclic Analogues of Combretastatin A4. ChemMedChem 2011; 6:1693-705. [DOI: 10.1002/cmdc.201100154] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Revised: 05/24/2011] [Indexed: 12/15/2022]
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32
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Gavara L, Saugues E, Anizon F, Moreau P. Regioselective synthesis of novel substituted indazole-5,6-diamine derivatives. Tetrahedron 2011. [DOI: 10.1016/j.tet.2011.01.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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33
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Cankařová N, Hlaváč J, Krchňák V. Recent Synthetic Approaches to 1H- and 2H-Indazoles. A Review. ORG PREP PROCED INT 2010. [DOI: 10.1080/00304948.2010.513898] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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34
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Palladium(II) complexes bearing the new pincer ligand 3,5-bis(indazol-2-ylmethyl)toluene; synthesis and catalytic properties. INORG CHEM COMMUN 2010. [DOI: 10.1016/j.inoche.2010.06.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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35
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Goikhman R, Jacques TL, Sames D. C-H bonds as ubiquitous functionality: a general approach to complex arylated pyrazoles via sequential regioselective C-arylation and N-alkylation enabled by SEM-group transposition. J Am Chem Soc 2010; 131:3042-8. [PMID: 19206533 DOI: 10.1021/ja8096114] [Citation(s) in RCA: 154] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Pyrazoles are important azole heteroarenes frequently found in pharmaceuticals and protein ligands, and there has been a growing interest in new synthetic methods for their preparation. We report the first catalytic intermolecular C-H arylation of pyrazoles, namely SEM-protected pyrazoles and N-alkylpyrazoles, which lays the foundation for a new approach to the synthesis of complex arylated pyrazoles, where new arene rings are directly attached to predetermined positions of the heteroarene nucleus ("topologically obvious synthesis"). Through a systematic search, we identified a palladium-pivalate catalytic system as the most effective protocol and mapped the reactivity of all three C-H bonds of the pyrazole (C-5 > C-4 >> C-3). To circumvent the low reactivity of the C-3 position, we developed a "SEM switch", which transposes the SEM-protecting group from one nitrogen to the other in one step, and in the process transforms the unreactive C-3 position to the reactive C-5 position. The SEM switch thus enables sequential arylation of C-5 and C-3 position, providing rapid access to protected or free 3,4,5-triarylpyrazoles (the C-4 arene ring is readily introduced by bromination and Suzuki coupling). Furthermore, N-alkylation of SEM-protected pyrazoles allows for regioselective introduction of the amine substituent, addressing the low regioselectivity of N-alkylation of pyrazoles lacking sufficient steric bias. Thus, the catalytic C-H arylation combined with the protecting group transposition and N-alkylation provides a rapid route to fully substituted pyrazoles with complete regiocontrol of all substituents. The particular strength of this strategy is the ability to commence the synthesis from either the parent pyrazole or practically any pyrazole intermediate.
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Affiliation(s)
- Roman Goikhman
- Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, USA
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36
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Chioua M, Soriano E, Samadi A, Marco-Contelles J. Studies on the acetylation of 3,6-diamino-1H-pyrazolo[3,4-b]pyridine-5-carbonitrile derivatives. J Heterocycl Chem 2010. [DOI: 10.1002/jhet.403] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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37
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Vernekar SKV, Hallaq HY, Clarkson G, Thompson AJ, Silvestri L, Lummis SCR, Lochner M. Toward biophysical probes for the 5-HT3 receptor: structure-activity relationship study of granisetron derivatives. J Med Chem 2010; 53:2324-8. [PMID: 20146481 PMCID: PMC4166935 DOI: 10.1021/jm901827x] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
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This report describes the synthesis and biological characterization of novel granisetron derivatives that are antagonists of the human serotonin (5-HT3A) receptor. Some of these substituted granisetron derivatives showed low nanomolar binding affinity and allowed the identification of positions on the granisetron core that might be used as attachment points for biophysical tags. A BODIPY fluorophore was appended to one such position and specifically bound to 5-HT3A receptors in mammalian cells.
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38
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Chandra T, Broderick WE, Broderick JB. An efficient deprotection of N-trimethylsilylethoxymethyl (SEM) groups from dinucleosides and dinucleotides. NUCLEOSIDES, NUCLEOTIDES & NUCLEIC ACIDS 2010; 29:132-43. [PMID: 20391200 PMCID: PMC4331121 DOI: 10.1080/15257771003612847] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
A convenient and efficient method for deprotection of N-(trimethyl)silylethoxymethyl (SEM) groups from thymidine dinucleoside and dinucleotide has been achieved. The SEM groups were easily removed in excellent yields from protected nucleosides, dinucleosides, and dinucleotides.
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Affiliation(s)
- Tilak Chandra
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA
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39
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Hurtado J, Carey DML, Muñoz-Castro A, Arratia-Pérez R, Quijada R, Wu G, Rojas R, Valderrama M. Chromium(III) complexes with terdentate 2,6-bis(azolylmethyl)pyridine ligands: Synthesis, structures and ethylene polymerization behavior. J Organomet Chem 2009. [DOI: 10.1016/j.jorganchem.2009.04.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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40
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Degnan AP, Conway CM, Dalterio RA, Macci R, Mercer SE, Schartman R, Xu C, Dubowchik GM, Macor JE. Carbamates as potent calcitonin gene-related peptide antagonists with improved solution stability. Bioorg Med Chem Lett 2009; 19:3555-8. [DOI: 10.1016/j.bmcl.2009.04.150] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2009] [Revised: 04/27/2009] [Accepted: 04/30/2009] [Indexed: 11/25/2022]
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41
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Unexpected product distributions in the synthesis of 2,6-bis-(indazolyl)pyridine and 2-(pyrazol-1-yl)-6-(indazolyl)pyridine. Tetrahedron Lett 2009. [DOI: 10.1016/j.tetlet.2009.03.035] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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42
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Caris R, Peoples BC, Valderrama M, Wu G, Rojas R. Mono and bimetallic nickel bromide complexes bearing azolate-imine ligands: Synthesis, structural characterization and ethylene polymerization studies. J Organomet Chem 2009. [DOI: 10.1016/j.jorganchem.2009.01.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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43
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Hari Y, Sone R, Aoyama T. Facile two-step synthesis of 3-substituted indazoles using diazo(trimethylsilyl)methylmagnesium bromide. Org Biomol Chem 2009; 7:2804-8. [DOI: 10.1039/b907796k] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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44
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Affiliation(s)
- Andreas Schmidt
- Clausthal University of Technology, Institute of Organic Chemistry, Leibnizstrasse 6, 38678 Clausthal‐Zellerfeld, Germany, Fax: +49‐5323‐722858
| | - Ariane Beutler
- Clausthal University of Technology, Institute of Organic Chemistry, Leibnizstrasse 6, 38678 Clausthal‐Zellerfeld, Germany, Fax: +49‐5323‐722858
| | - Bohdan Snovydovych
- Clausthal University of Technology, Institute of Organic Chemistry, Leibnizstrasse 6, 38678 Clausthal‐Zellerfeld, Germany, Fax: +49‐5323‐722858
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45
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Chapter 5.4 Five membered ring systems: with more than one N atom. ACTA ACUST UNITED AC 2008. [DOI: 10.1016/s0959-6380(08)80010-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/09/2023]
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46
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Mills AD, Maloney P, Hassanein E, Haddadin MJ, Kurth MJ. Synthesis of a library of 2-alkyl-3-alkyloxy-2H-indazole-6-carboxamides. ACTA ACUST UNITED AC 2007; 9:171-7. [PMID: 17206845 DOI: 10.1021/cc060109o] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A library of 200 2-alkyl-3-alkyloxy-2H-indazole-6-carboxamides was synthesized using parallel solution-phase methods. The indazole cyclization reaction was optimized for library production with the best yields resulting from controlled alcohol/water solvent ratios. The key step, a heterocyclization reaction, proceeds by N,N-bond formation and delivers the 2H-indazole scaffold. Automated preparative HPLC was utilized to provide pure compounds on a 10+ mg scale.
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Affiliation(s)
- Aaron D Mills
- Department of Chemistry, University of California, One Shields Avenue, Davis, California 95616-5295, USA
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