RESUMEN
We report a general and functional-group-tolerant method for the Cu-catalyzed amination of base-sensitive aryl bromides including substrates possessing acidic functional groups and small five-membered heteroarenes. The results presented herein substantially expand the scope of Cu-catalyzed C-N coupling reactions. The combination of L8, an anionic N1,N2-diarylbenzene-1,2-diamine ligand, along with the mild base NaOTMS leads to the formation of a stable yet reactive catalyst that resists deactivation from coordination to heterocycles or charged intermediates. This system enables the use of low catalyst and ligand loadings. Exploiting the differences in nucleophile deprotonation in C-O and C-N coupling reactions catalyzed by Cu·L8 we developed a method to chemoselectively N- and O-arylate a variety of amino alcohol substrates. Employing NaOt-Bu as the base resulted exclusively in C-O coupling when the amino alcohols featured primary alcohols and more hindered amines or aniline groups. Utilizing NaOTMS enabled the ability to override the steric-based selectivity of these reactions completely and exclusively promoted C-N coupling regardless of the structure of the amino alcohol. The ability to invert the observed chemoselectivity is distinct from previously described methods that require protecting group manipulations or rely entirely on steric effects to control reactivity. These results substantially improve the scope of Cu-catalyzed C-N coupling reactions using N1,N2-diarylbenzene-1,2-diamine ligands and introduce a new chemoselective method to arylate amino alcohols.
Asunto(s)
Amino Alcoholes , Cobre , Cobre/química , Catálisis , Aminación , Amino Alcoholes/química , Estructura Molecular , Bromuros/química , Hidrocarburos Bromados/química , LigandosRESUMEN
We describe an optimization and scale-up of the 45-membered macrocyclic thioether peptide BMS-986189 utilizing solid-phase peptide synthesis (SPPS). Improvements to linear peptide isolation, macrocyclization, and peptide purification were demonstrated to increase the throughput and purification of material on scale and enabled the synthesis and purification of >60 g of target peptide. Taken together, not only these improvements resulted in a 28-fold yield increase from the original SPPS approach, but also the generality of this newly developed SPPS purification sequence has found application in the synthesis and purification of other macrocyclic thioether peptides.
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Compuestos Macrocíclicos , Péptidos , Técnicas de Síntesis en Fase Sólida , Sulfuros , Sulfuros/química , Sulfuros/síntesis química , Compuestos Macrocíclicos/química , Compuestos Macrocíclicos/síntesis química , Péptidos/química , Péptidos/síntesis química , Péptidos Cíclicos/química , Péptidos Cíclicos/síntesis química , Estructura Molecular , CiclizaciónRESUMEN
We disclose the development of a Cu-catalyzed C-O coupling method utilizing a new N1,N2-diarylbenzene-1,2-diamine ligand, L8. Under optimized reaction conditions, structurally diverse aryl and heteroaryl bromides underwent efficient coupling with a variety of alcohols at room temperature using an L8-based catalyst. Notably, the L8-derived catalyst exhibited enhanced activity when compared to the L4-based system previously disclosed for C-N coupling, namely the ability to functionalize aryl bromides containing acidic functional groups. Mechanistic studies demonstrate that C-O coupling utilizing L8 â Cu involves rate-limiting alkoxide transmetallation, resulting in a mechanism of C-O bond formation that is distinct from previously described Pd-, Cu-, or Ni-based systems. This lower energy pathway leads to rapid C-O bond formation; a 7-fold increase relative to what is seen with other ligands. The results presented in this report overcome limitations in previously described C-O coupling methods and introduce a new ligand that we anticipate may be useful in other Cu-catalyzed C-heteroatom bond-forming reactions.
RESUMEN
PURPOSE: A same-day PET imaging agent capable of measuring PD-L1 status in tumors is an important tool for optimizing PD-1 and PD-L1 treatments. Herein we describe the discovery and evaluation of a novel, fluorine-18 labeled macrocyclic peptide-based PET ligand for imaging PD-L1. METHODS: [18F]BMS-986229 was synthesized via copper mediated click-chemistry to yield a PD-L1 PET ligand with picomolar affinity and was tested as an in-vivo tool for assessing PD-L1 expression. RESULTS: Autoradiography showed an 8:1 binding ratio in L2987 (PD-L1 (+)) vs. HT-29 (PD-L1 (-)) tumor tissues, with >90% specific binding. Specific radioligand binding (>90%) was observed in human non-small-cell lung cancer (NSCLC) and cynomolgus monkey spleen tissues. Images of PD-L1 (+) tissues in primates were characterized by high signal-to-noise, with low background signal in non-expressing tissues. PET imaging enabled clear visualization of PD-L1 expression in a murine model in vivo, with 5-fold higher uptake in L2987 (PD-L1 (+)) than in control HT-29 (PD-L1 (-)) tumors. Moreover, this imaging agent was used to measure target engagement of PD-L1 inhibitors (peptide or mAb), in PD-L1 (+) tumors as high as 97%. CONCLUSION: A novel 18F-labeled macrocyclic peptide radioligand was developed for PET imaging of PD-L1 expressing tissues that demonstrated several advantages within a nonhuman primate model when compared directly to adnectin- or mAb-based ligands. Clinical studies are currently evaluating [18F]BMS-986229 to measure PD-L1 expression in tumors.
Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas , Dominio de Fibronectina del Tipo III , Radioisótopos de Flúor , Neoplasias Pulmonares , Proteínas Recombinantes , Humanos , Ratones , Animales , Antígeno B7-H1/metabolismo , Ligandos , Macaca fascicularis/metabolismo , Tomografía de Emisión de Positrones/métodos , Péptidos/químicaRESUMEN
PURPOSE: In cancer immunotherapy, the blockade of the interaction between programmed death-1 and its ligand (PD-1:PD-L1) has proven to be one of the most promising strategies. However, as mechanisms of resistance to PD-1/PD-L1 inhibition include variability in tumor cell PD-L1 expression in addition to standard tumor biopsy PD-L1 immunohistochemistry (IHC), a comprehensive and quantitative approach for measuring PD-L1 expression is required. Herein, we report the development and characterization of an 18F-PD-L1-binding macrocyclic peptide as a PET tracer for the comprehensive evaluation of tumor PD-L1 expression in cancer patients. PROCEDURES: 18F-BMS-986229 was characterized for PD-L1 expression assessment by autoradiography or PET imaging. 18F-BMS-986229 was utilized to evaluate tumor PD-L1 target engagement in competition with a macrocyclic peptide inhibitor of PD-L1 (BMS-986189) over a range of doses using PET imaging. A whole-body radiation dosimetry study of 18F-BMS-986229 in healthy non-human primates (NHPs) was performed. RESULTS: In vitro autoradiography showed an 8:1 binding ratio in L2987(PD-L1 +) vs. HT-29 (PD-L1-) tumors, more than 90% of which could be blocked with 1 nM of BMS-986189. Ex vivo autoradiography showed that 18F-BMS-986229 detection was penetrant over a series of sections spanning the entire L2987 tumor. In vivo PET imaging in mice demonstrated a 5:1 tracer uptake ratio (at 90-100 min after tracer administration) in L2987 vs. HT-29 tumors and demonstrated 83%-93% specific binding of BMS-986189 within those dose ranges. In a healthy NHP dosimetry study, the resultant whole-body effective dose was 0.025 mSv/MBq. CONCLUSION: 18F-BMS-986229 has been preclinically characterized and exhibits high target specificity, low background uptake, and a short blood half-life supportive of same day imaging in the clinic. As the PET tracer, 18F-BMS-986229 shows promise in the quantification of PD-L1 expression, and its use in monitoring longitudinal changes in patients may provide insights into PD-1:PD-L1 immuno-therapy treatment outcomes.
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Antígeno B7-H1 , Neoplasias , Humanos , Animales , Ratones , Antígeno B7-H1/metabolismo , Receptor de Muerte Celular Programada 1 , Tomografía de Emisión de Positrones/métodos , Radiometría , PéptidosRESUMEN
A method for deoxyfluorination of aliphatic primary, secondary, and tertiary alcohols is reported, employing a nontrigonal phosphorus triamide for base-free alcohol activation in conjunction with an organic soluble fluoride donor and a triarylborane fluoride shuttling catalyst. Mechanistic experiments are consistent with a reaction that proceeds by the collapse of an oxyphosphonium fluoroborate ion pair with fluoride transfer. The substrate scope complements existing deoxyfluorination methods and enables the preparation of homochiral secondary and tertiary alkylfluorides by stereoinversion of the substrate alcohol.
RESUMEN
The discovery of a pan-genotypic hepatitis C virus (HCV) NS3/4A protease inhibitor based on a P1-P3 macrocyclic tripeptide motif is described. The all-carbon tether linking the P1-P3 subsites of 21 is functionalized with alkyl substituents, which are shown to effectively modulate both potency and absorption, distribution, metabolism, and excretion (ADME) properties. The CF3Boc-group that caps the P3 amino moiety was discovered to be an essential contributor to metabolic stability, while positioning a methyl group at the C1 position of the P1' cyclopropyl ring enhanced plasma trough values following oral administration to rats. The C7-fluoro, C6-CD3O substitution pattern of the P2* isoquinoline heterocycle of 21 was essential to securing the targeted potency, pharmacokinetic (PK), and toxicological profiles. The C6-CD3O redirected metabolism away from a problematic pathway, thereby circumventing the time-dependent cytochrome P (CYP) 450 inhibition observed with the C6-CH3O prototype.
Asunto(s)
Antivirales/farmacología , Péptidos Cíclicos/farmacología , Inhibidores de Serina Proteinasa/farmacología , Proteínas no Estructurales Virales/antagonistas & inhibidores , Animales , Antivirales/síntesis química , Antivirales/metabolismo , Antivirales/farmacocinética , Células CHO , Cricetulus , Descubrimiento de Drogas , Estabilidad de Medicamentos , Hepacivirus/efectos de los fármacos , Hepacivirus/enzimología , Pruebas de Sensibilidad Microbiana , Microsomas Hepáticos/metabolismo , Estructura Molecular , Péptidos Cíclicos/síntesis química , Péptidos Cíclicos/metabolismo , Péptidos Cíclicos/farmacocinética , Ratas , Inhibidores de Serina Proteinasa/síntesis química , Inhibidores de Serina Proteinasa/metabolismo , Inhibidores de Serina Proteinasa/farmacocinética , Relación Estructura-ActividadRESUMEN
The direct union of primary, secondary, and tertiary carboxylic acids with a chiral glyoxylate-derived sulfinimine provides rapid access into a variety of enantiomerically pure α-amino acids (>85 examples). Characterized by operational simplicity, this radical-based reaction enables the modular assembly of exotic α-amino acids, including both unprecedented structures and those of established industrial value. The described method performs well in high-throughput library synthesis, and has already been implemented in three distinct medicinal chemistry campaigns.
Asunto(s)
Aminoácidos/síntesis química , Radicales Libres/química , EstereoisomerismoRESUMEN
A series of tripeptidic acylsulfonamide inhibitors of HCV NS3 protease were prepared that explored structure-activity relationships (SARs) at the P4 position, and their in vitro and in vivo properties were evaluated. Enhanced potency was observed in a series of P4 ureas; however, the PK profiles of these analogues were less than optimal. In an effort to overcome the PK shortcomings, modifications to the P3-P4 junction were made. This included a strategy in which one of the two urea N-H groups was either N-methylated or replaced with an oxygen atom. The former approach provided a series of regioisomeric N-methylated ureas while the latter gave rise to P4 reverse carbamates, both of which retained potent NS3 inhibitory properties while relying upon an alternative H-bond donor topology. Details of the SARs and PK profiles of these analogues are provided.
Asunto(s)
Antivirales/química , Carbamatos/química , Inhibidores de Proteasas/química , Urea/química , Proteínas no Estructurales Virales/antagonistas & inhibidores , Animales , Antivirales/farmacocinética , Antivirales/farmacología , Sitios de Unión , Semivida , Hepacivirus/efectos de los fármacos , Hepacivirus/enzimología , Humanos , Enlace de Hidrógeno , Hígado/metabolismo , Simulación de Dinámica Molecular , Inhibidores de Proteasas/farmacocinética , Inhibidores de Proteasas/farmacología , Estructura Terciaria de Proteína , Ratas , Relación Estructura-Actividad , Proteínas no Estructurales Virales/metabolismoRESUMEN
The design and synthesis of potent, tripeptidic acylsulfonamide inhibitors of HCV NS3 protease that contain a difluoromethyl cyclopropyl amino acid at P1 are described. A cocrystal structure of 18 with a NS3/4A protease complex suggests the presence of a H-bond between the polarized C-H of the CHF2 moiety and the backbone carbonyl of Leu135 of the enzyme. Structure-activity relationship studies indicate that this H-bond enhances enzyme inhibitory potency by 13- and 17-fold compared to the CH3 and CF3 analogues, respectively, providing insight into the deployment of this unique amino acid.
RESUMEN
Naphthalene-linked P2-P4 macrocycles within a tri-peptide-based acyl sulfonamide chemotype have been synthesized and found to inhibit HCV NS3 proteases representing genotypes 1a and 1b with single digit nanomolar potency. The pharmacokinetic profile of compounds in this series was optimized through structural modifications along the macrocycle tether as well as the P1 subsite. Ultimately a compound with oral bioavailability of 100% in rat, and a long half-life in plasma was obtained. However, compounds in this macrocyclic series exhibited cardiac effects in an isolated rabbit heart model and for this reason further optimization efforts were discontinued.
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Antivirales/química , Compuestos Macrocíclicos/química , Naftalenos/química , Inhibidores de Proteasas/química , Proteínas no Estructurales Virales/antagonistas & inhibidores , Administración Oral , Animales , Antivirales/farmacología , Evaluación Preclínica de Medicamentos , Semivida , Corazón/efectos de los fármacos , Corazón/fisiología , Hepacivirus/efectos de los fármacos , Hepacivirus/enzimología , Compuestos Macrocíclicos/farmacocinética , Compuestos Macrocíclicos/farmacología , Microsomas Hepáticos/metabolismo , Conformación Molecular , Inhibidores de Proteasas/farmacocinética , Inhibidores de Proteasas/farmacología , Conejos , Ratas , Proteínas no Estructurales Virales/metabolismoRESUMEN
A thermodynamic approach to peptide macrocyclization inspired by the cyclization of non-ribosomal peptide aldehydes is presented. The method provides access to structurally diverse macrocycles by exploiting the reactivity of transient macrocyclic peptide imines toward inter- and intramolecular nucleophiles. Reactions are performed in aqueous media, in the absence of side chain protecting groups, and are tolerant of all proteinogenic functional groups. Macrocyclic products bearing non-native and rigidifying structural motifs, isotopic labels, and a variety of bioorthogonal handles are prepared, along with analogues of four distinct natural products. Structural interrogation of the linear and macrocyclic peptides using variable-temperature NMR and circular dichroism suggests that preorganization of linear substrates is not a prerequisite for macrocyclization.
RESUMEN
A series of potent and novel acylsulfonamide-bearing triazines were synthesized and the structure-activity relationships (SARs) as HCV entry inhibitors were evaluated. This acylsulfonamide series was derived from an early lead, 4-(4-(1-(4-chlorophenyl)cyclopropylamino)-6-(2,2,2-trifluoroethoxy)-1,3,5-triazin-2-ylamino)benzoic acid wherein the carboxylic acid was replaced with an acylsulfonamide moiety. This structural modification provided a class of compounds which projected an additional vector off the terminus of the acylsulfonamide functionality as a means to drive activity. This effort led to the discovery of potent analogues within this series that demonstrated sub-nanomolar EC50 values in the HCV pseudotype particle (HCVpp) assay.
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Antivirales/farmacología , Hepacivirus/efectos de los fármacos , Fusión de Membrana/efectos de los fármacos , Triazinas/farmacología , Animales , Antivirales/química , Antivirales/farmacocinética , Hepacivirus/fisiología , Humanos , Ratas , Relación Estructura-Actividad , Triazinas/química , Triazinas/farmacocinéticaRESUMEN
The design and synthesis of a series of tripeptide acylsulfonamides as potent inhibitors of the HCV NS3/4A serine protease is described. These analogues house a C4 aryl, C4 hydroxy-proline at the S2 position of the tripeptide scaffold. Information relating to structure-activity relationships as well as the pharmacokinetic and cardiovascular profiles of these analogues is provided.
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Antivirales/química , Hepacivirus/enzimología , Oligopéptidos/química , Inhibidores de Proteasas/química , Proteínas no Estructurales Virales/antagonistas & inhibidores , Animales , Antivirales/farmacocinética , Antivirales/farmacología , Semivida , Corazón/efectos de los fármacos , Hepacivirus/efectos de los fármacos , Humanos , Técnicas In Vitro , Oligopéptidos/farmacocinética , Oligopéptidos/farmacología , Prolina/química , Inhibidores de Proteasas/farmacocinética , Inhibidores de Proteasas/farmacología , Conejos , Ratas , Relación Estructura-Actividad , Sulfonamidas/química , Proteínas no Estructurales Virales/metabolismoRESUMEN
Pd-catalyzed ß-C-H functionalizations of carboxylic acid derivatives using an auxiliary as a directing group have been extensively explored in the past decade. In comparison to the most widely used auxiliaries in asymmetric synthesis, the simplicity and practicality of the auxiliaries developed for C-H activation remains to be improved. We previously developed a simple N-methoxyamide auxiliary to direct ß-C-H activation, albeit this system was not compatible with carboxylic acids containing α-hydrogen atoms. Herein we report the development of a pyridine-type ligand that overcomes this limitation of the N-methoxyamide auxiliary, leading to a significant improvement of ß-arylation of carboxylic acid derivatives, especially α-amino acids. The arylation using this practical auxiliary is applied to the gram-scale syntheses of unnatural amino acids, bioactive molecules, and chiral bis(oxazoline) ligands.
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Aminoácidos/química , Alanina/química , Aminoácidos/síntesis química , Ácidos Carboxílicos/química , Catálisis , Técnicas de Química Sintética , Hidrógeno/química , Ligandos , Paladio/química , Fenilalanina/química , PiridinasRESUMEN
Asunaprevir (ASV; BMS-650032), a low nanomolar inhibitor of the hepatitis C virus (HCV) NS3 protease, is currently under development, in combination with other direct-acting antiviral (DAA) agents for the treatment of chronic HCV infection. Extensive nonclinical and pharmacokinetic studies have been conducted to characterize the ADME properties of ASV. ASV has a moderate to high clearance in preclinical species. In vitro reaction phenotyping studies demonstrated that the oxidative metabolism of ASV is primarily mediated via CYP3A4; however, studies in bile-duct cannulated rats and dogs suggest that biliary elimination may contribute to overall ASV clearance. ASV is shown to have hepatotropic disposition in all preclinical species tested (liver to plasma ratios >40). The translation of in vitro replicon potency to clinical viral load decline for a previous lead BMS-605339 was leveraged to predict a human dose of 2 mg BID for ASV. Clinical drug-drug interaction (DDI) studies have shown that at therapeutically relevant concentrations of ASV the potential for a DDI is minimal. The need for an interferon free treatment combined with ASV's initial clinical trial data support development of ASV as part of a fixed dose combination for the treatment of patients chronically infected with HCV genotype 1.
Asunto(s)
Antivirales/farmacocinética , Hepacivirus/enzimología , Isoquinolinas/farmacocinética , Inhibidores de Proteasas/farmacocinética , Sulfonamidas/farmacocinética , Proteínas no Estructurales Virales/antagonistas & inhibidores , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/antagonistas & inhibidores , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/metabolismo , Animales , Bilis/metabolismo , Disponibilidad Biológica , Citocromo P-450 CYP3A/metabolismo , Inhibidores Enzimáticos del Citocromo P-450/farmacología , Perros , Hepacivirus/efectos de los fármacos , Hepatocitos/metabolismo , Humanos , Hígado/metabolismo , Macaca fascicularis , Masculino , Ratones , Microsomas Hepáticos/metabolismo , Oxidación-Reducción , Ratas , Ratas Sprague-DawleyRESUMEN
BMS-605339 is a potent HCV NS3 protease inhibitor that suppresses hepatitis C virus replication and was under investigation as an oral agent for the treatment of this disease. In vitro and in vivo studies were conducted in mouse, rat, dog, and monkey to characterize the pharmacokinetics and metabolism of this compound. BMS-605339 was predicted to be a moderate clearance compound in the human, based on human microsomal and hepatocyte data. Nearly all metabolism of BMS-605339 was oxidative; CYP3A4 is likely to play a key role in the metabolic clearance of this compound. Moderate to high Caco-2 permeability was observed for this compound, with the potential for P-glycoprotein involvement. The oral bioavailability of BMS-605339 was variable and dose dependent, suggesting low absorption, possibly because of transporter involvement. BMS-605339 possesses low intrinsic aqueous solubility and, in both rat and dog, administration of an aqueous suspension suggested that BMS-605339 absorption is likely solubility limited. Liver exposure of BMS-605339 was consistently higher than plasma exposure in all species tested (mouse, rat, and dog), indicating the potential for active uptake into hepatocytes. The overall preclinical pharmacokinetic profile supported the selection and development of BMS-605339 as a clinical candidate.
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Antivirales/farmacocinética , Isoquinolinas/farmacocinética , Sulfonamidas/farmacocinética , Proteínas no Estructurales Virales/antagonistas & inhibidores , Animales , Disponibilidad Biológica , Células CACO-2 , Perros , Humanos , Técnicas In Vitro , Ratones , Ratones Endogámicos BALB C , Ratas , Ratas Sprague-DawleyRESUMEN
The discovery of asunaprevir (BMS-650032, 24) is described. This tripeptidic acylsulfonamide inhibitor of the NS3/4A enzyme is currently in phase III clinical trials for the treatment of hepatitis C virus infection. The discovery of 24 was enabled by employing an isolated rabbit heart model to screen for the cardiovascular (CV) liabilities (changes to HR and SNRT) that were responsible for the discontinuation of an earlier lead from this chemical series, BMS-605339 (1), from clinical trials. The structure-activity relationships (SARs) developed with respect to CV effects established that small structural changes to the P2* subsite of the molecule had a significant impact on the CV profile of a given compound. The antiviral activity, preclincial PK profile, and toxicology studies in rat and dog supported clinical development of BMS-650032 (24).
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Antivirales/uso terapéutico , Hepatitis C/tratamiento farmacológico , Isoquinolinas/uso terapéutico , Inhibidores de Proteasas/uso terapéutico , Sulfonamidas/uso terapéutico , Proteínas no Estructurales Virales/antagonistas & inhibidores , Animales , Antivirales/sangre , Antivirales/química , Perros , Humanos , Isoquinolinas/sangre , Isoquinolinas/química , Modelos Moleculares , Inhibidores de Proteasas/sangre , Inhibidores de Proteasas/química , Conejos , Ratas , Sulfonamidas/sangre , Sulfonamidas/químicaRESUMEN
Comprehensive structure activity relationship (SAR) studies were conducted on a focused screening hit, 2-(methylthio)-3-(phenylsulfonyl)-4H-pyrido[1,2-a]pyrimidin-4-imine (1, IC50: 4.0 nM), as 5-HT6 selective antagonists. Activity was improved some 2-4 fold when small, electron-donating groups were added to the central core as observed in 19, 20 and 26. Molecular docking of key compounds in a homology model of the human 5-HT6 receptor was used to rationalize our structure-activity relationship (SAR) findings. In pharmacokinetic experiments, compound 1 displayed good brain uptake in rats following intra-peritoneal administration, but limited oral bioavailability.
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Enfermedad de Alzheimer/tratamiento farmacológico , Iminas/farmacocinética , Receptores de Serotonina/uso terapéutico , Animales , Humanos , Iminas/farmacología , Simulación del Acoplamiento Molecular , Ratas , Relación Estructura-ActividadRESUMEN
The discovery of BMS-605339 (35), a tripeptidic inhibitor of the NS3/4A enzyme, is described. This compound incorporates a cyclopropylacylsulfonamide moiety that was designed to improve the potency of carboxylic acid prototypes through the introduction of favorable nonbonding interactions within the S1' site of the protease. The identification of 35 was enabled through the optimization and balance of critical properties including potency and pharmacokinetics (PK). This was achieved through modulation of the P2* subsite of the inhibitor which identified the isoquinoline ring system as a key template for improving PK properties with further optimization achieved through functionalization. A methoxy moiety at the C6 position of this isoquinoline ring system proved to be optimal with respect to potency and PK, thus providing the clinical compound 35 which demonstrated antiviral activity in HCV-infected patients.