RESUMO
Frequently referred to as the 'magic methyl effect', the installation of methyl groups-especially adjacent (α) to heteroatoms-has been shown to dramatically increase the potency of biologically active molecules1-3. However, existing methylation methods show limited scope and have not been demonstrated in complex settings1. Here we report a regioselective and chemoselective oxidative C(sp3)-H methylation method that is compatible with late-stage functionalization of drug scaffolds and natural products. This combines a highly site-selective and chemoselective C-H hydroxylation with a mild, functional-group-tolerant methylation. Using a small-molecule manganese catalyst, Mn(CF3PDP), at low loading (at a substrate/catalyst ratio of 200) affords targeted C-H hydroxylation on heterocyclic cores, while preserving electron-neutral and electron-rich aryls. Fluorine- or Lewis-acid-assisted formation of reactive iminium or oxonium intermediates enables the use of a mildly nucleophilic organoaluminium methylating reagent that preserves other electrophilic functionalities on the substrate. We show this late-stage C(sp3)-H methylation on 41 substrates housing 16 different medicinally important cores that include electron-rich aryls, heterocycles, carbonyls and amines. Eighteen pharmacologically relevant molecules with competing sites-including drugs (for example, tedizolid) and natural products-are methylated site-selectively at the most electron rich, least sterically hindered position. We demonstrate the syntheses of two magic methyl substrates-an inverse agonist for the nuclear receptor RORc and an antagonist of the sphingosine-1-phosphate receptor-1-via late-stage methylation from the drug or its advanced precursor. We also show a remote methylation of the B-ring carbocycle of an abiraterone analogue. The ability to methylate such complex molecules at late stages will reduce synthetic effort and thereby expedite broader exploration of the magic methyl effect in pursuit of new small-molecule therapeutics and chemical probes.
Assuntos
Produtos Biológicos/química , Produtos Biológicos/síntese química , Carbono/química , Técnicas de Química Sintética , Hidrogênio/química , Preparações Farmacêuticas/química , Preparações Farmacêuticas/síntese química , Androstenos/síntese química , Androstenos/química , Catálise , Agonismo Inverso de Drogas , Elétrons , Flúor/química , Hidroxilação , Ácidos de Lewis/química , Manganês/química , Metilação , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/agonistas , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/antagonistas & inibidores , Oxazolidinonas/síntese química , Oxazolidinonas/química , Oxirredução , Receptores de Esfingosina-1-Fosfato/antagonistas & inibidores , Tetrazóis/síntese química , Tetrazóis/químicaRESUMO
Cyclic amines are ubiquitous structural motifs found in pharmaceuticals and biologically active natural products, making methods for their elaboration via direct C-H functionalization of considerable synthetic value. Herein, we report the development of an iron-based biocatalytic strategy for enantioselective α-C-H functionalization of pyrrolidines and other saturated N-heterocycles via a carbene transfer reaction with diazoacetone. Currently unreported for organometallic catalysts, this transformation can be accomplished in high yields, high catalytic activity, and high stereoselectivity (up to 99:1 e.r. and 20,350 TON) using engineered variants of cytochrome P450 CYP119 from Sulfolobus solfataricus. This methodology was further extended to enable enantioselective α-C-H functionalization in the presence of ethyl diazoacetate as carbene donor (up to 96:4 e.r. and 18,270 TON), and the two strategies were combined to achieve a one-pot as well as a tandem dual C-H functionalization of a cyclic amine substrate with enzyme-controlled diastereo- and enantiodivergent selectivity. This biocatalytic approach is amenable to gram-scale synthesis and can be applied to drug scaffolds for late-stage C-H functionalization. This work provides an efficient and tunable method for direct asymmetric α-C-H functionalization of saturated N-heterocycles, which should offer new opportunities for the synthesis, discovery, and optimization of bioactive molecules.
Assuntos
Aminas , Estereoisomerismo , Catálise , Biocatálise , Aminas/químicaRESUMO
Secondary metabolites synthesized by non-ribosomal peptide synthetases display diverse and complex topologies and possess a range of biological activities. Much of this diversity derives from a synthetic strategy that entails pre- and post-assembly oxidation of both the chiral amino acid building blocks and the assembled peptide scaffolds. The vancomycin biosynthetic pathway is an excellent example of the range of oxidative transformations that can be performed by the iron-containing enzymes involved in its biosynthesis. However, because of the challenges associated with using such oxidative enzymes to carry out chemical transformations in vitro, chemical syntheses guided by these principles have not been fully realized in the laboratory. Here we report that two small-molecule iron catalysts are capable of facilitating the targeted C-H oxidative modification of amino acids and peptides with preservation of α-centre chirality. Oxidation of proline to 5-hydroxyproline furnishes a versatile intermediate that can be transformed to rigid arylated derivatives or flexible linear carboxylic acids, alcohols, olefins and amines in both monomer and peptide settings. The value of this C-H oxidation strategy is demonstrated in its capacity for generating diversity: four 'chiral pool' amino acids are transformed to twenty-one chiral unnatural amino acids representing seven distinct functional group arrays; late-stage C-H functionalizations of a single proline-containing tripeptide furnish eight tripeptides, each having different unnatural amino acids. Additionally, a macrocyclic peptide containing a proline turn element is transformed via late-stage C-H oxidation to one containing a linear unnatural amino acid.
Assuntos
Aminoácidos/química , Aminoácidos/síntese química , Ferro/química , Ferro/farmacologia , Peptídeos/química , Peptídeos/síntese química , Catálise/efeitos dos fármacos , Hidroxilação/efeitos dos fármacos , Compostos Macrocíclicos/química , Estrutura Molecular , Prolina/química , EstereoisomerismoRESUMO
The synthesis of mono-, di-, and trifluoromethyl aryl ethers by fluorodecarboxylation of the corresponding carboxylic acids is reported. AgF2 induces decarboxylation of aryloxydifluoroacetic acids, and AgF, either generated in situ or added separately, serves as a source of fluorine to generate the fluorodecarboxylation products. The addition of 2,6-difluoropyridine increased the reactivity of AgF2 , thereby increasing the range of functional groups and electronic properties of the aryl groups that are tolerated. The reaction conditions used for the formation of trifluoromethyl aryl ethers also served to form difluoromethyl and monofluoromethyl aryl ethers.
RESUMO
Optimization of the ADME properties of a series of 2,4-diaminopyrimidine-5-carboxamide inhibitors of Sky kinase resulted in the identification of highly selective compounds with properties suitable for use as in vitro and in vivo tools to probe the effects of Sky inhibition.
Assuntos
Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Pirimidinas/química , Pirimidinas/farmacologia , Receptores Proteína Tirosina Quinases/antagonistas & inibidores , Amidas/química , Amidas/farmacologia , Animais , Humanos , Camundongos , Receptores Proteína Tirosina Quinases/química , Relação Estrutura-Atividade , Especificidade por SubstratoRESUMO
We report the SAR around a series of 2,4-diaminopyrimidine-5-carboxamide inhibitors of Sky kinase. 2-Aminophenethyl analogs demonstrate excellent potency but moderate kinase selectivity, while 2-aminobenzyl analogs that fill the Ala571 subpocket exhibit good inhibition activity and excellent kinase selectivity.
Assuntos
Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Pirimidinas/química , Pirimidinas/farmacologia , Receptores Proteína Tirosina Quinases/antagonistas & inibidores , Amidas/química , Amidas/farmacologia , Animais , Humanos , Camundongos , Relação Estrutura-Atividade , Especificidade por SubstratoRESUMO
The optimization for selectivity and central receptor occupancy for a series of spirocyclic azetidine-piperidine inverse agonists of the ghrelin receptor is described. Decreased mAChR muscarinic M2 binding was achieved by use of a chiral indane in place of a substituted benzylic group. Compounds with desirable balance of human in vitro clearance and ex vivo central receptor occupancy were discovered by incorporation of heterocycles. Specifically, heteroaryl rings with nitrogen(s) vicinal to the indane linkage provided the most attractive overall properties.
Assuntos
Sistema Nervoso Central/efeitos dos fármacos , Receptores de Grelina/antagonistas & inibidores , Sequência de Aminoácidos , Animais , Sítios de Ligação , Agonismo Inverso de Drogas , Compostos Heterocíclicos/química , Compostos Heterocíclicos/farmacologia , Humanos , Indanos/química , Indanos/farmacologia , Concentração Inibidora 50 , Isomerismo , Estrutura Molecular , Ligação Proteica/efeitos dos fármacos , Ratos , Relação Estrutura-AtividadeRESUMO
The synthesis of 4',6'-dihydrospiro[piperidine-4,5'-pyrazolo[3,4-c]pyridin]-7'(2'H)-one-based acetyl-CoA carboxylase inhibitors is reported. The hitherto unknown N-2 tert-butyl pyrazolospirolactam core was synthesized from ethyl 3-amino-1H-pyrazole-4-carboxylate in a streamlined 10-step synthesis requiring only one chromatography procedure. The described synthetic strategy provides pyrazolo-fused spirolactams from halogenated benzylic arenes and cyclic carboxylates. Key steps include a regioselective pyrazole alkylation providing the N-2 tert-butyl pyrazole and a Curtius rearrangement under both conventional and flow conditions to install the hindered amine via a stable and isolable isocyanate. Finally, a Parham-type cyclization was used to furnish the desired spirolactam. An analogous route provided efficient access to the related N-1 isopropyl lactam series. Elaboration of the lactam cores via amidation enabled synthesis of novel ACC inhibitors and the identification of potent analogues.
Assuntos
Acetil-CoA Carboxilase/antagonistas & inibidores , Acetil-CoA Carboxilase/química , Lactamas/química , Lactamas/síntese química , Piperidinas/química , Piperidinas/síntese química , Pirazóis/química , Piridonas/química , Piridonas/síntese química , Alquilação , Ciclização , Estrutura Molecular , EstereoisomerismoRESUMO
We report the discovery of a novel series of spiroindoline-based inhibitors of Sky kinase that bind in the ATP-binding site and exhibit high levels of kinome selectivity through filling the Ala571-subpocket. These inhibitors exhibit moderate oral bioavailability in the rat due to low absorption across the gut wall.
Assuntos
Química Farmacêutica/métodos , Intestinos/efeitos dos fármacos , Receptores Proteína Tirosina Quinases/antagonistas & inibidores , Absorção , Trifosfato de Adenosina/química , Administração Oral , Animais , Sítios de Ligação , Disponibilidade Biológica , Cristalografia por Raios X/métodos , Desenho de Fármacos , Humanos , Concentração Inibidora 50 , Modelos Químicos , Agregação Plaquetária , Ratos , Receptores Proteína Tirosina Quinases/químicaRESUMO
New cholecystokinin-1 receptor (CCK1R) agonist 'triggers' were identified using iterative library synthesis. Structural activity relationship studies led to the discovery of compound 10e, a potent CCK1R agonist that demonstrated robust weight loss in a diet-induced obese rat model with very low systemic exposure. Pharmacokinetic data suggest that efficacy is primarily driven through activation of CCK1R's located within the intestinal wall.
Assuntos
Amidas/síntese química , Descoberta de Drogas , Piperidinas/síntese química , Receptor de Colecistocinina A/agonistas , Amidas/química , Amidas/farmacologia , Animais , Células Cultivadas , Modelos Animais de Doenças , Humanos , Concentração Inibidora 50 , Masculino , Camundongos , Camundongos Obesos , Piperidinas/química , Piperidinas/farmacologia , Ligação Proteica/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Relação Estrutura-Atividade , Redução de Peso/efeitos dos fármacosRESUMO
Isopropyl 9-anti-[5-cyano-6-(2-methyl-pyridin-3-yloxy)-pyrimidin-4-yloxy]-3-oxa-7-aza-bicyclo[3.3.1]nonane-7-carboxylate (1) represents a prototypic compound from a lead chemical series of G protein-coupled receptor 119 agonists, intended for treatment of type 2 diabetes. When compound 1 was incubated with NADPH-supplemented human liver microsomes in the presence of glutathione, two thioether conjugates M4-1 and M5-1 were observed. Omission of NADPH from the microsomal incubations prevented the formation of M5-1 but not M4-1. The formation of M4-1 was also discerned in incubations of 1 and glutathione with human liver cytosol, partially purified glutathione transferase, and in phosphate buffer at pH 7.4. M4-1 was isolated, and its structure ascertained from LC-MS/MS and NMR analysis. The mass spectral and NMR data suggested that M4-1 was obtained from a nucleophilic displacement of the 6-(2-methylpyridin-3-yloxy) group in 1 by glutathione. In addition, mass spectral studies revealed that M5-1 was derived from an analogous displacement reaction on a monohydroxylated metabolite of 1; the regiochemistry of hydroxylation was established to be on the isopropyl group. Of great interest were the findings that replacement of the 5-cyano group in 1 with a 5-methyl group resulted in 2, which was practically inert toward reaction with glutathione. This observation suggests that the electron-withdrawing potential of the C5 cyano group serves to increase the electrophilicity of the C6 carbon (via stabilization of the transition state) and favors reaction with the nucleophilic thiol. The mechanistic insights gained from these studies should assist medicinal chemistry efforts toward the design of analogs that retain primary pharmacology but are latent toward reaction with biological nucleophiles, thus mitigating the potential for toxicological outcome due to adduction with glutathione or proteins.
Assuntos
Glutationa/metabolismo , Microssomos Hepáticos/efeitos dos fármacos , Microssomos Hepáticos/metabolismo , Pirimidinas/metabolismo , Receptores Acoplados a Proteínas G/agonistas , Animais , Diabetes Mellitus Tipo 2/tratamento farmacológico , Glutationa/química , Cavalos , Humanos , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Estrutura Molecular , Pirimidinas/químicaRESUMO
The scarcity of practical methods for aldehyde synthesis in chemistry necessitates the development of mild, selective procedures. Carboxylic acid reductases catalyze aldehyde formation from stable carboxylic acid precursors in an aqueous solution. Carboxylic acid reductases were employed to catalyze aldehyde formation in a cell-free system with activation energy and reducing equivalents provided through auxiliary proteins for ATP and NADPH recycling. In situ product removal was used to suppress over-reduction due to background enzyme activities, and an N-protected 4-formyl-piperidine pharma synthon was prepared in 61% isolated yield. This is the first report of preparative aldehyde synthesis with carboxylic acid reductases employing crude, commercially available enzyme preparations.
Assuntos
Aldeídos , Preparações Farmacêuticas , Ácidos Carboxílicos , Catálise , NADPRESUMO
Sickle cell disease (SCD) is a genetic disorder caused by a single point mutation (ß6 Glu â Val) on the ß-chain of adult hemoglobin (HbA) that results in sickled hemoglobin (HbS). In the deoxygenated state, polymerization of HbS leads to sickling of red blood cells (RBC). Several downstream consequences of polymerization and RBC sickling include vaso-occlusion, hemolytic anemia, and stroke. We report the design of a noncovalent modulator of HbS, clinical candidate PF-07059013 (23). The seminal hit molecule was discovered by virtual screening and confirmed through a series of biochemical and biophysical studies. After a significant optimization effort, we arrived at 23, a compound that specifically binds to Hb with nanomolar affinity and displays strong partitioning into RBCs. In a 2-week multiple dose study using Townes SCD mice, 23 showed a 37.8% (±9.0%) reduction in sickling compared to vehicle treated mice. 23 (PF-07059013) has advanced to phase 1 clinical trials.
Assuntos
Anemia Falciforme/tratamento farmacológico , Hemoglobina A/efeitos dos fármacos , Hemoglobina Falciforme/efeitos dos fármacos , Quinolinas/farmacologia , Quinolinas/uso terapêutico , Animais , Eritrócitos/metabolismo , Camundongos , Oxigênio/metabolismo , Quinolinas/químicaRESUMO
Aiming to improve upon previously disclosed Factor Xa inhibitors, a series of 4,4-disubstituted pyrrolidine-1,2-dicarboxamides were explored with the intent of increasing the projected human half-life versus 5 (projected human t(1/2)=6 h). A stereospecific route to compounds containing a 4-aryl-4-hydroxypyrrolidine scaffold was developed, resulting in several compounds that demonstrated an increase in the half-life as well as an increase in the in vitro potency compared to 5. Reported herein is the discovery of 26, containing a (2R,4S)-4-hydroxy-4-(2,4-difluorophenyl)-pyrrolidine scaffold, which is a selective, orally bioavailable, efficacious Factor Xa inhibitor that appears suitable for a once-daily dosing (projected human t(1/2)=23 h).
Assuntos
Pirrolidinas/farmacologia , Administração Oral , Cristalografia por Raios X , Meia-Vida , Humanos , Pirrolidinas/administração & dosagem , Pirrolidinas/farmacocinéticaRESUMO
The synthesis and properties of the bridged piperidine (oxaazabicyclo) compounds 8, 9, and 11 are described. A conformational analysis of these structures is compared with the representative GPR119 ligand 1. These results and the differences in agonist pharmacology are used to formulate a conformation-based hypothesis to understand activation of the GPR119 receptor. We also show for these structures that the agonist pharmacology in rat masks the important differences in human pharmacology.
Assuntos
Compostos Azabicíclicos/química , Compostos Azabicíclicos/farmacologia , Pirimidinas/química , Pirimidinas/farmacologia , Receptores Acoplados a Proteínas G/agonistas , Animais , Compostos Azabicíclicos/síntese química , Teste de Tolerância a Glucose , Humanos , Conformação Molecular , Pirimidinas/síntese química , Ratos , Receptores Acoplados a Proteínas G/antagonistas & inibidores , Especificidade da Espécie , Estereoisomerismo , Relação Estrutura-AtividadeRESUMO
An extraordinarily potent and hepatoselective class of HMG-CoA reductase inhibitors containing a pyrazole core was recently reported; however, its development was hampered by a long and difficult synthetic route. We attempted to circumvent this obstacle by preparing closely related analogs wherein the key dihydroxyheptanoic acid sidechain was tethered to the pyrazole core via an oxygen linker ('oxypyrazoles'). This minor change reduced the total number of synthetic steps from 14 to 7. Although the resulting analogs maintained much of the in vitro and cell activity of the pyrazoles, inferior in vivo activity precluded further development. Caco-2 cell permeability data suggest that enhanced cellular efflux of the oxypyrazoles relative to the pyrazoles may be responsible for the poor in vivo activity.
Assuntos
Desenho de Fármacos , Hidroximetilglutaril-CoA Redutases/metabolismo , Inibidores de Hidroximetilglutaril-CoA Redutases/química , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Pirazóis/química , Pirazóis/farmacologia , Animais , Linhagem Celular , Cricetinae , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/síntese química , Fígado/efeitos dos fármacos , Fígado/enzimologia , Estrutura Molecular , Células Musculares/efeitos dos fármacos , Células Musculares/enzimologia , Pirazóis/síntese química , Ratos , Relação Estrutura-AtividadeRESUMO
A novel series of pyrrolidine-1,2-dicarboxamides was discovered as factor Xa inhibitors using structure-based drug design. This series consisted of a neutral 4-chlorophenylurea P1, a biphenylsulfonamide P4 and a D-proline scaffold (1, IC(50) = 18 nM). Optimization of the initial hit resulted in an orally bioavailable, subnanomolar inhibitor of factor Xa (13, IC(50) = 0.38 nM), which was shown to be efficacious in a canine electrolytic model of thrombosis with minimal bleeding.
Assuntos
Antitrombina III/química , Química Farmacêutica/métodos , Ácido Pirrolidonocarboxílico/farmacologia , Administração Oral , Animais , Antitrombina III/farmacologia , Cristalização , Cães , Desenho de Fármacos , Humanos , Concentração Inibidora 50 , Modelos Químicos , Modelos Moleculares , Ligação Proteica , Ácido Pirrolidonocarboxílico/química , Relação Estrutura-Atividade , Fatores de TempoRESUMO
Herein, we report the discovery of novel, proline-based factor Xa inhibitors containing a neutral P1 chlorophenyl pharmacophore. Through the additional incorporation of 1-(4-amino-3-fluoro-phenyl)-1H-pyridin-2-one 22, as a P4 pharmacophore, we discovered compound 7 (PD 0348292). This compound is a selective, orally bioavailable, efficacious FXa inhibitor that is currently in phase II clinical trials for the treatment and prevention of thrombotic disorders.
Assuntos
Antitrombina III/síntese química , Antitrombina III/farmacologia , Piridonas/síntese química , Piridonas/farmacologia , Pirrolidinas/síntese química , Pirrolidinas/farmacologia , Animais , Anticoagulantes/síntese química , Anticoagulantes/farmacocinética , Anticoagulantes/farmacologia , Antitrombina III/farmacocinética , Cristalografia por Raios X , Cães , Humanos , Masculino , Piridonas/farmacocinética , Pirrolidinas/farmacocinética , Coelhos , Ratos , Relação Estrutura-AtividadeRESUMO
The activated factor VII/tissue factor complex (FVIIa/TF) is known to play a key role in the formation of blood clots. Inhibition of this complex may lead to new antithrombotic drugs. A fluoropyridine-based series of FVIIa/TF inhibitors was discovered which utilized a diisopropylamino group for binding in the S2 and S3 binding pockets of the active site of the enzyme complex. In this series, an enhancement in binding affinity was observed by substitution at the 5-position of the hydroxybenzoic acid sidechain. An X-ray crystal structure indicates that amides at this position may increase inhibitor binding affinity through interactions with the S1'/S2' pocket.
Assuntos
Inibidores Enzimáticos/farmacologia , Fator VIIa/antagonistas & inibidores , Piridinas/farmacologia , Tromboplastina/antagonistas & inibidores , Cristalografia por Raios X , Avaliação Pré-Clínica de Medicamentos , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Modelos Moleculares , Estrutura Molecular , Piridinas/síntese química , Piridinas/química , Relação Estrutura-AtividadeRESUMO
Herein, we report on the identification of three potent glycine and related amino acid-based series of FXa inhibitors containing a neutral P1 chlorophenyl pharmacophore. A X-ray crystal structure has shown that constrained glycine derivatives with optimized N-substitution can greatly increase hydrophobic interactions in the FXa active site. Also, the substitution of a pyridone ring for a phenylsulfone ring in the P4 sidechain resulted in an inhibitor with enhanced oral bioavailability.