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Kaplan JA, Blum SA. Iodination-Group-Transfer Reactions to Generate Trisubstituted Iodoalkenes with Regio- and Stereochemical Control. J Org Chem 2023; 88:13236-13247. [PMID: 37656489 DOI: 10.1021/acs.joc.3c01495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
Abstract
The regio- and stereodefined synthesis of trisubstituted alkenes remains a significant synthetic challenge. Herein, a method is developed for producing regio- and stereodefined trisubstituted iodoalkenes by diverting intermediates from an iodination-electrophilic-cyclization mechanism. Specifically, cyclized sulfonium ion-pair intermediates are diverted to alkenes by ring-opening with nucleophilic iodide. Alternatively, scavenging of the iodide by AgOTf prevents ring-opening, enabling isolation of the sulfonium ion-pair intermediate. Isolation of the ion pair enables access to complementary reactivity, including ring-opening by alternative nucleophiles (i.e., amines), yielding trisubstituted acyclic alkenes and an example acyclic tetrasubstituted alkene. X-ray crystallographic determination of reaction intermediates and products confirms that the initial electrophilic-cyclization step sets the stereo- and regiochemistry of the product. The products serve as synthetic building blocks by readily participating in downstream functionalization reactions, including oxidation, palladium-catalyzed cross-coupling, and nucleophilic displacement.
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Affiliation(s)
- Joseph A Kaplan
- Department of Chemistry, University of California, Irvine, Irvine, California 92697, United States
| | - Suzanne A Blum
- Department of Chemistry, University of California, Irvine, Irvine, California 92697, United States
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Woltornist RA, Collum DB. Ketone Enolization with Sodium Hexamethyldisilazide: Solvent- and Substrate-Dependent E- Z Selectivity and Affiliated Mechanisms. J Am Chem Soc 2021; 143:17452-17464. [PMID: 34643382 PMCID: PMC10042305 DOI: 10.1021/jacs.1c06529] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Ketone enolization by sodium hexamethyldisilazide (NaHMDS) shows a marked solvent and substrate dependence. Enolization of 2-methyl-3-pentanone reveals E-Z selectivities in Et3N/toluene (20:1), methyl-t-butyl ether (MTBE, 10:1), N,N,N',N″,N″-pentamethyldiethylenetriamine (PMDTA)/toluene (8:1), TMEDA/toluene (4:1), diglyme (1:1), DME (1:22), and tetrahydrofuran (THF) (1:90). Control experiments show slow or nonexistent stereochemical equilibration in all solvents except THF. Enolate trapping with Me3SiCl/Et3N requires warming to -40 °C whereas Me3SiOTf reacts within seconds. In situ enolate trapping at -78 °C using preformed NaHMDS/Me3SiCl mixtures is effective in Et3N/toluene yet fails in THF by forming (Me3Si)3N. Rate studies show enolization via mono- and disolvated dimers in Et3N/toluene, disolvated dimers in TMEDA, trisolvated monomers in THF/toluene, and free ions with PMDTA. Density functional theory computations explore the selectivities via the E- and Z-based transition structures. Failures of theory-experiment correlations of ionic fragments were considerable even when isodesmic comparisons could have canceled electron correlation errors. Swapping 2-methyl-3-pentanone with a close isostere, 2-methylcyclohexanone, causes a fundamental change in the mechanism to a trisolvated-monomer-based enolization in THF.
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Affiliation(s)
- Ryan A Woltornist
- Department of Chemistry and Chemical Biology Baker Laboratory, Cornell University, Ithaca, New York 14853-1301, United States
| | - David B Collum
- Department of Chemistry and Chemical Biology Baker Laboratory, Cornell University, Ithaca, New York 14853-1301, United States
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3
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Woltornist RA, Collum DB. Aggregation and Solvation of Sodium Hexamethyldisilazide: Across the Solvent Spectrum. J Org Chem 2021; 86:2406-2422. [PMID: 33471993 PMCID: PMC8011853 DOI: 10.1021/acs.joc.0c02546] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We report solution structures of sodium hexamethyldisilazide (NaHMDS) solvated by >30 standard solvents (ligands). These include: toluene, benzene, and styrene; triethylamine and related trialkylamines; pyrrolidine as a representative dialkylamine; dialkylethers including THF, tert-butylmethyl ether, and diethyl ether; dipolar ligands such as DMF, HMPA, DMSO, and DMPU; a bifunctional dipolar ligand nonamethylimidodiphosphoramide (NIPA); polyamines N,N,N',N'-tetramethylenediamine (TMEDA), N,N,N',N″,N″-pentamethyldiethylenetriamine (PMDTA), N,N,N',N'-tetramethylcyclohexanediamine (TMCDA), and 2,2'-bipyridine; polyethers 12-crown-4, 15-crown-5, 18-crown-6, and diglyme; 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]hexacosane ([2.2.2] cryptand); and tris[2-(2-methoxyethoxy)ethyl]amine (TDA-1). Combinations of 1H, 13C, 15N, and 29Si NMR spectroscopies, the method of continuous variations, X-ray crystallography, and density functional theory (DFT) computations reveal ligand-modulated aggregation to give mixtures of dimers, monomers, triple ions, and ion pairs. 15N-29Si coupling constants distinguish dimers and monomers. Solvation numbers are determined by a combination of solvent titrations, observed free and bound solvent in the slow exchange limit, and DFT computations. The relative abilities of solvents to compete in binary mixtures often match that predicted by conventional wisdom but with some exceptions and evidence of both competitive and cooperative (mixed) solvation. Crystal structures of a NaHMDS cryptate ion pair and a 15-crown-5-solvated monomer are included. Results are compared with those for lithium hexamethyldisilazide, lithium diisopropylamide, and sodium diisopropylamide.
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Affiliation(s)
- Ryan A Woltornist
- Department of Chemistry and Chemical Biology Baker Laboratory, Cornell University, Ithaca, New York 14853-1301, United States
| | - David B Collum
- Department of Chemistry and Chemical Biology Baker Laboratory, Cornell University, Ithaca, New York 14853-1301, United States
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Lee HJ, Cao Y, Pham V, Blackwood E, Wilson C, Evangelista M, Klijn C, Stokoe D, Settleman J. Ras–MEK Signaling Mediates a Critical Chk1-Dependent DNA Damage Response in Cancer Cells. Mol Cancer Ther 2017; 16:694-704. [DOI: 10.1158/1535-7163.mct-16-0504] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 12/09/2016] [Accepted: 12/27/2016] [Indexed: 11/16/2022]
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Perez M, Elangovan S, Spannenberg A, Junge K, Beller M. Molecularly Defined Manganese Pincer Complexes for Selective Transfer Hydrogenation of Ketones. CHEMSUSCHEM 2017; 10:83-86. [PMID: 27791342 DOI: 10.1002/cssc.201601057] [Citation(s) in RCA: 120] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Indexed: 06/06/2023]
Abstract
For the first time an easily accessible and well-defined manganese N,N,N-pincer complex catalyzes the transfer hydrogenation of a broad range of ketones with good to excellent yields. This cheap earth abundant-metal based catalyst provides access to useful secondary alcohols without the need of hydrogen gas. Preliminary investigations to explore the mechanism of this transformation are also reported.
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Affiliation(s)
- Marc Perez
- Leibniz-Institut für Katalyse e.V. an der Universität Rostock, Albert-Einstein Straße 29a, Rostock, 18059, Germany
| | - Saravanakumar Elangovan
- Leibniz-Institut für Katalyse e.V. an der Universität Rostock, Albert-Einstein Straße 29a, Rostock, 18059, Germany
| | - Anke Spannenberg
- Leibniz-Institut für Katalyse e.V. an der Universität Rostock, Albert-Einstein Straße 29a, Rostock, 18059, Germany
| | - Kathrin Junge
- Leibniz-Institut für Katalyse e.V. an der Universität Rostock, Albert-Einstein Straße 29a, Rostock, 18059, Germany
| | - Matthias Beller
- Leibniz-Institut für Katalyse e.V. an der Universität Rostock, Albert-Einstein Straße 29a, Rostock, 18059, Germany
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Ronco C, Martin AR, Demange L, Benhida R. ATM, ATR, CHK1, CHK2 and WEE1 inhibitors in cancer and cancer stem cells. MEDCHEMCOMM 2016; 8:295-319. [PMID: 30108746 DOI: 10.1039/c6md00439c] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 11/25/2016] [Indexed: 12/15/2022]
Abstract
DNA inevitably undergoes a high number of damages throughout the cell cycle. To preserve the integrity of the genome, cells have developed a complex enzymatic machinery aimed at sensing and repairing DNA lesions, pausing the cell cycle to provide more time to repair, or induce apoptosis if damages are too severe. This so-called DNA-damage response (DDR) is yet considered as a major source of resistance to DNA-damaging treatments in oncology. Recently, it has been hypothesized that cancer stem cells (CSC), a sub-population of cancer cells particularly resistant and with tumour-initiating ability, allow tumour re-growth and cancer relapse. Therefore, DDR appears as a relevant target to sensitize cancer cells and cancer stem cells to classical radio- and chemotherapies as well as to overcome resistances. Moreover, the concept of synthetic lethality could be particularly efficiently exploited in DDR. Five kinases play pivotal roles in the DDR: ATM, ATR, CHK1, CHK2 and WEE1. Herein, we review the drugs targeting these proteins and the inhibitors used in the specific case of CSC. We also suggest molecules that may be of interest for preclinical and clinical researchers studying checkpoint inhibition to sensitize cancer and cancer stem cells to DNA-damaging treatments.
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Affiliation(s)
- Cyril Ronco
- Université Côte d'Azur , CNRS , Institut de Chimie de Nice , UMR7272 - Parc Valrose , 06108 Nice Cedex 2 , France . ; ; Tel: +33 4 92076143
| | - Anthony R Martin
- Université Côte d'Azur , CNRS , Institut de Chimie de Nice , UMR7272 - Parc Valrose , 06108 Nice Cedex 2 , France . ; ; Tel: +33 4 92076143
| | - Luc Demange
- Université Côte d'Azur , CNRS , Institut de Chimie de Nice , UMR7272 - Parc Valrose , 06108 Nice Cedex 2 , France . ; ; Tel: +33 4 92076143.,Université Paris Descartes , Sorbonne Paris Cité , UFR des Sciences Pharmaceutiques , 4 avenue de l'Observatoire , Paris Fr-75006 , France.,Université Paris Descartes , Sorbonne Paris Cité , UFR Biomédicale des Saints Pères , 45 rue des Saints Pères , France
| | - Rachid Benhida
- Université Côte d'Azur , CNRS , Institut de Chimie de Nice , UMR7272 - Parc Valrose , 06108 Nice Cedex 2 , France . ; ; Tel: +33 4 92076143
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Infante JR, Hollebecque A, Postel-Vinay S, Bauer TM, Blackwood EM, Evangelista M, Mahrus S, Peale FV, Lu X, Sahasranaman S, Zhu R, Chen Y, Ding X, Murray ER, Schutzman JL, Lauchle JO, Soria JC, LoRusso PM. Phase I Study of GDC-0425, a Checkpoint Kinase 1 Inhibitor, in Combination with Gemcitabine in Patients with Refractory Solid Tumors. Clin Cancer Res 2016; 23:2423-2432. [PMID: 27815358 DOI: 10.1158/1078-0432.ccr-16-1782] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 10/06/2016] [Accepted: 10/11/2016] [Indexed: 11/16/2022]
Abstract
Purpose: Chk1 inhibition potentiates DNA-damaging chemotherapy by overriding cell-cycle arrest and genome repair. This phase I study evaluated the Chk1 inhibitor GDC-0425 given in combination with gemcitabine to patients with advanced solid tumors.Experimental Design: Patients received GDC-0425 alone for a 1-week lead-in followed by 21-day cycles of gemcitabine plus GDC-0425. Gemcitabine was initially administered at 750 mg/m2 (Arm A), then increased to 1,000 mg/m2 (Arm B), on days 1 and 8 in a 3 + 3 + 3 dose escalation to establish maximum tolerated dose (MTD). GDC-0425 was initially administered daily for three consecutive days; however, dosing was abbreviated to a single day on the basis of pharmacokinetics and tolerability. TP53 mutations were evaluated in archival tumor tissue. On-treatment tumor biopsies underwent pharmacodynamic biomarker analyses.Results: Forty patients were treated with GDC-0425. The MTD of GDC-0425 was 60 mg when administered approximately 24 hours after gemcitabine 1,000 mg/m2 Dose-limiting toxicities included thrombocytopenia (n = 5), neutropenia (n = 4), dyspnea, nausea, pyrexia, syncope, and increased alanine aminotransferase (n = 1 each). Common related adverse events were nausea (48%); anemia, neutropenia, vomiting (45% each); fatigue (43%); pyrexia (40%); and thrombocytopenia (35%). The GDC-0425 half-life was approximately 15 hours. There were two confirmed partial responses in patients with triple-negative breast cancer (TP53-mutated) and melanoma (n = 1 each) and one unconfirmed partial response in a patient with cancer of unknown primary origin.Conclusions: Chk1 inhibition with GDC-0425 in combination with gemcitabine was tolerated with manageable bone marrow suppression. The observed preliminary clinical activity warrants further investigation of this chemopotentiation strategy. Clin Cancer Res; 23(10); 2423-32. ©2016 AACR.
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Affiliation(s)
- Jeffrey R Infante
- Sarah Cannon Research Institute/Tennessee Oncology, Nashville, Tennessee.
| | - Antoine Hollebecque
- Départemement d'Innovation Thérapeutique et des Essais Précoces (DITEP), Gustave Roussy, Université Paris Saclay, Villejuif, France
| | - Sophie Postel-Vinay
- Départemement d'Innovation Thérapeutique et des Essais Précoces (DITEP), Gustave Roussy, Université Paris Saclay, Villejuif, France.,INSERM, U981, Villejuif, France
| | - Todd M Bauer
- Sarah Cannon Research Institute/Tennessee Oncology, Nashville, Tennessee
| | | | | | - Sami Mahrus
- Genentech, Inc., South San Francisco, California
| | | | - Xuyang Lu
- Genentech, Inc., South San Francisco, California
| | | | - Rui Zhu
- Genentech, Inc., South San Francisco, California
| | - Yuan Chen
- Genentech, Inc., South San Francisco, California
| | - Xiao Ding
- Genentech, Inc., South San Francisco, California
| | | | | | | | - Jean-Charles Soria
- Départemement d'Innovation Thérapeutique et des Essais Précoces (DITEP), Gustave Roussy, Université Paris Saclay, Villejuif, France.,INSERM, U981, Villejuif, France
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Osborne JD, Matthews TP, McHardy T, Proisy N, Cheung KMJ, Lainchbury M, Brown N, Walton MI, Eve PD, Boxall KJ, Hayes A, Henley AT, Valenti MR, De Haven Brandon AK, Box G, Jamin Y, Robinson SP, Westwood IM, van Montfort RLM, Leonard PM, Lamers MBAC, Reader JC, Aherne GW, Raynaud FI, Eccles SA, Garrett MD, Collins I. Multiparameter Lead Optimization to Give an Oral Checkpoint Kinase 1 (CHK1) Inhibitor Clinical Candidate: (R)-5-((4-((Morpholin-2-ylmethyl)amino)-5-(trifluoromethyl)pyridin-2-yl)amino)pyrazine-2-carbonitrile (CCT245737). J Med Chem 2016; 59:5221-37. [PMID: 27167172 DOI: 10.1021/acs.jmedchem.5b01938] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Multiparameter optimization of a series of 5-((4-aminopyridin-2-yl)amino)pyrazine-2-carbonitriles resulted in the identification of a potent and selective oral CHK1 preclinical development candidate with in vivo efficacy as a potentiator of deoxyribonucleic acid (DNA) damaging chemotherapy and as a single agent. Cellular mechanism of action assays were used to give an integrated assessment of compound selectivity during optimization resulting in a highly CHK1 selective adenosine triphosphate (ATP) competitive inhibitor. A single substituent vector directed away from the CHK1 kinase active site was unexpectedly found to drive the selective cellular efficacy of the compounds. Both CHK1 potency and off-target human ether-a-go-go-related gene (hERG) ion channel inhibition were dependent on lipophilicity and basicity in this series. Optimization of CHK1 cellular potency and in vivo pharmacokinetic-pharmacodynamic (PK-PD) properties gave a compound with low predicted doses and exposures in humans which mitigated the residual weak in vitro hERG inhibition.
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