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1.
Angew Chem Int Ed Engl ; 62(10): e202215899, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36602033

RESUMO

The deprotonative functionalization of α,α-difluoromethyl ketones is described herein. Using a catalytic organosuperbase and a silane additive, the corresponding difluoroenolate could be generated and trapped with aldehydes to deliver various α,α-difluoro-ß-hydroxy ketones in high yields. This new strategy tolerates numerous functional groups and represents the access to the difluoroenolate by direct deprotonation of the difluoromethyl unit. The diastereoselective version of the reaction was also investigated with d.r. up to 93 : 7. Several transformations were performed to demonstrate the synthetic potential of these α,α-difluoro-ß-hydroxy ketones. In addition, this method has been extended to the use of other electrophiles such as imines and chalcogen derivatives, and a difluoromethyl sulfoxide as nucleophile, thus leading to a diversity of difluoromethylene compounds.

2.
Dynamis (Granada) ; 42(2): 397-421, 2022.
Artigo em Inglês | IBECS | ID: ibc-223253

RESUMO

This article examines the history of the policy concerning a class of diseases called intractable diseases in Japan with a particular focus on the roles of patient support groups in firstly legitimizing the grouping of such diseases and then shaping the nature of the support that the Japanese Ministry of Health and Welfare provided to the patients and their families affected by them. The Ministry started its policy on intractable diseases in 1972, predating the enactment of the 1983 Orphan Drug Act in the United States, which is known to be one of the most important events for the international rare diseases community. This policy decision was triggered by the emergence of subacute myelo-optic neuropathy (SMON) as a social problem in the country in the late 1960s. The Ministry first made its support available to patients with this particular disease and, as a result of a series of actions from patient support groups and their medical and political supporters, the same support was made available to those considered to be in similarly difficult circumstances. The way in which the support was arranged, however, turned out to be structurally divisive, inviting the patient groups to negotiate with the national and local governments separately depending on subject matters, and for about three decades since the start of the policy, they struggled to present their unified voice in the country. The governmental support for intractable diseases was finally revised in the mid-2000s, but as this article demonstrates, that became possible only after the patient groups came to realize the need of presenting a unified voice in their effort to improve the lives of those affected (AU)


Assuntos
Humanos , História do Século XX , Política de Saúde/história , Doenças Raras/história , Japão
3.
J Org Chem ; 85(12): 7916-7924, 2020 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-32427486

RESUMO

The highly enantioselective copper/chiral phosphine-catalyzed hydro-, bora-, and carbo-metalations of difluorocyclopropenes with PHMS [H-Si], H-BPin, (BPin)2, and (CH3)2Zn [Zn-Me] are shown to regiodivergently afford highly enantioenriched and functionalized difluorocyclopropanes. These examples can be viewed as the first successful syntheses of "chiral" gem-dimethyl and tert-butyl analogues.

4.
New Genet Soc ; 39(2): 148-172, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32406397

RESUMO

Social scientists have observed previously that patient support groups began to have significant influence over both research and clinical services of medical genetics in the early 2000s. This observation led to the idea of genetic citizenship, suggesting that the active participation and intervention of patient support groups in the rapidly growing field of medicine marked the emergence of a new form of citizenship. To understand how this citizenship emerged, this paper examines the development of umbrella organizations of genetic support groups in the USA and the UK. The historical analysis demonstrates that the ways in which these organizations developed differ considerably, and that their visions and activities reflected the different structural and cultural organizations of medical genetics in their respective countries. By recognizing the early work of these organizations as citizenship projects, this article argues that they helped rather different forms of genetic citizenship to emerge in the two countries.

5.
J Org Chem ; 84(19): 12281-12291, 2019 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-31483649

RESUMO

The new synthetic methodologies for perfluoroaryl-substituted (diaryl)methylphosphonates, -phosphinates via nucleophilic aromatic substitution (SNAr) were developed. Benzylphosphonate and α-fluorobenzylphosphonate reacted with a wide variety of perfluoroarenes via SNAr reaction. The reaction took place quickly and gave perfluoroarylated phosphonates in high yields. Highly diastereoselective SNAr reaction with binaphthyl-based chiral phosphinates was further carried out.

6.
Soc Hist Med ; 32(3): 609-630, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31384102

RESUMO

This paper examines the history of orphan drug policy, from the emergence of 'orphans' in the American pharmaceutical market in the 1960s, through the debates and agitations that resulted in the passage of the US Orphan Drug Act of 1983, to attempts in the 1990s to prevent abuse of that Act and restore its original intentions. Although an increased number of drugs for rare diseases have since been developed and marketed, the extremely high price of some such drugs is considered a major public health issue internationally. The present paper traces the origins of this issue to the market-based approach to resolving the problem of orphan drugs embodied in the 1983 Act. The paper also makes visible an alternative trajectory that existed for a while in the United Kingdom but was eventually abandoned in order to help the biotechnology industry grow in the context of an increasingly integrated European drug market.

7.
Org Lett ; 21(9): 3387-3391, 2019 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-31002256

RESUMO

Chiral C2-symmetric phosphinic acids were designed based on sterically demanding and helical chiral perfluoroalkyl groups at the closest α-position advancing asymmetric reaction environment and catalytic activity. The perfluoroalkyl catalysts, [(CF3)2F2] and [(C2F5)2F2] phosphinic acids, were synthesized via a stereoselective addition/cyclization sequence of methyl phosphinate and deoxofluorination. These new classes of Brønsted acid catalysts were applied to an asymmetric Friedel-Crafts reaction to give up to 89% yield and 82% R-enantioselectivity, which is higher than those obtained with the parent phosphoric acid (42% and 55.5% S).

8.
J Org Chem ; 84(10): 6483-6490, 2019 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-30942589

RESUMO

Iron-catalyzed cross-coupling difluoromethylations of the Grignard reagents with difluoroiodomethane provide various aromatic difluoromethyl products in good yields, not employing sterically demanding ligands. Difluoromethylations proceed within 30 min at -20 °C with 2.0 equiv of the Grignard reagents and FeCl3 or Fe(acac)3 (2.5 mol %). Mechanistic investigations clarify difluoromethyl radical intervention; Fe(0) ate is initially generated. Single-electron transfer from Fe(0) ate to difluoroiodomethane takes place. Recombination with aryl groups gives Ar-CF2Hs. The catalyst can be regenerated by the Grignard reagents.

9.
Org Lett ; 21(4): 1093-1097, 2019 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-30698981

RESUMO

Copper(I)-mediated heptafluoroisopropylation of aryl halides (ArX: X = I, Br) is demonstrated using copper(I) carboxylates and a bis(heptafluoroisopropyl)zinc reagent Zn( i-C3F7)2(dmf)2, prepared from heptafluoroisopropyl iodide and diethylzinc. The air-tolerant solid heptafluoroisopropylzinc reagent is advantageous to conduct simple synthetic operations and successful to give the corresponding heptafluoroisopropyl arene derivatives via transmetalation to copper(I) center. The newly developed copper(I)-mediated heptafluoroisopropylation process can be advanced to the copper(I)-catalysis by silver carboxylate salts and complementary to the precedent radical-based processes.

10.
Org Lett ; 20(23): 7353-7357, 2018 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-30277079

RESUMO

Gold(I)-catalyzed highly enantioselective intermolecular [4 + 2] cycloaddition is shown with ynones and cyclohexadiene. Various bicyclo[2.2.2]octadiene derivatives are produced in high yields (up to 99%) with good enantioselectivity (up to 96% ee). Key to the success is generation of the gem-digold terminal alkyne as a catalytic on-cycle species. As proof of the gem-digold catalysis, a positive nonlinear effect is clarified between the ee's of the ligand and the cycloadduct.

11.
Chem Asian J ; 13(19): 2842-2846, 2018 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-30160029

RESUMO

The highly enantioselective Diels-Alder reaction of acetylenic dienophiles is shown to be effectively catalyzed by cationic chiral palladium complexes. Not only the degree but also the sense of enantioselectivity critically depends on the steric demand of ligands. Computational analyses indicate that the steric demand does not affect the endo/exo-selectivity but the enantioface selectivity of dienes.

12.
Chem Asian J ; 13(19): 2838-2841, 2018 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-30079984

RESUMO

Highly enantioselective [3+2] cycloaddition of ynones and nitrones has been developed. Very bulky ligand, DTBM-SEGPHOS, was used for an effective asymmetric induction over distal reaction centers on the linear ynone dipolarophile and for prevention of PdII catalyst deactivation by coordination of the nitrones. The reaction has wide scope of substrates in both ynones and nitrones.

13.
Org Lett ; 20(17): 5340-5343, 2018 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-30130118

RESUMO

The nickel-catalyzed cross-coupling difluoromethylation of the Grignard reagents with difluoroiodomethane is shown to provide the corresponding aromatic difluoromethyl products in excellent to moderate yields. The difluoromethylation proceeds smoothly within 1 h at room temperature with 1.5 equiv of the Grignard reagents in the presence of Ni(cod)2/TMEDA (2.5-0.5 mol %). Mechanistic studies clarify that the oxidative addition of the Ni(0) catalyst to difluoroiodomethane provides the TMEDA-Ni(II)(CF2H)I complex. This intermediate is transformed to TMEDA-Ni(II)(CF2H)Ph via transmetalation with PhMgBr. The reductive elimination takes place to give the aromatic cross-coupling difluoromethylation product along with regeneration of the TMEDA-Ni(0) catalyst. Electron paramagnetic resonance (EPR) and radical clock analyses of the nickel-catalyzed reaction provide no EPR active Ni(I) and Ni(III) species at around g = 2 and only a trace amount of the cyclization product.

14.
Angew Chem Int Ed Engl ; 57(28): 8608-8613, 2018 07 09.
Artigo em Inglês | MEDLINE | ID: mdl-29790272

RESUMO

A 1,3-diphosphacyclobutane-2,4-diyl contains a unique unsaturated cyclic unit, and the presence of radical-type centers have been expected as a source of functionality. This study demonstrates that the P-heterocyclic singlet biradical captures muonium (Mu=[µ+ e- ]), the light isotope of a hydrogen radical, to generate an observable P-heterocyclic paramagnetic species. Investigation of a powder sample of 2,4-bis(2,4,6-tri-t-butylphenyl)-1-t-butyl-3-benzyl-1,3-diphosphacyclobutane-2,4-diyl using muon (avoided) level-crossing resonance (µLCR) spectroscopy revealed that muonium adds to the cyclic P2 C2 unit. The muon hyperfine coupling constant (Aµ ) indicated that the phosphorus atom bearing the t-butyl group trapped muonium to provide a metastable P-heterocyclic radical involving the ylidic MuP(<)=C moiety. The observed regioselective muonium addition correlates the canonical formula of 1,3-diphosphacyclobutane-2,4-diyl.

15.
Beilstein J Org Chem ; 14: 576-582, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29623119

RESUMO

The catalytic asymmetric methylation of fluoroalkylated pyruvates is shown with dimethylzinc as a methylating reagent in the presence of a copper catalyst bearing a chiral phosphine ligand. This is the first catalytic asymmetric methylation to synthesize various α-fluoroalkylated tertiary alcohols with CF3, CF2H, CF2Br, and n-C n F2n+1 (n = 2, 3, 8) groups in good-to-high yields and enantioselectivities. Axial backbones and substituents on phosphorus atoms of chiral phosphine ligands critically influence the enantioselectivity. Moreover, the methylation of simple perfluoroalkylated ketones is found to be facilitated by only chiral phosphines without copper.

16.
Chem Asian J ; 13(7): 830-837, 2018 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-29377570

RESUMO

9-Phosphaanthracene (dibenzo[b,e]phosphorin, acridophosphine) has attracted interest as one of the heavier acenes. Herein, we demonstrate an efficient synthetic process that provides air-tolerant 1,8-bis(trifluoromethyl)-9-phosphaanthracenes. The sterically encumbered and electron-withdrawing trifluoromethyl (CF3 ) groups are quite advantageous not only to stabilize the intrinsically unstable heavier unsaturated phosphorus atom but also to facilitate construction of the phosphinine skeleton based on a putative increase in aromaticity. The isolated 9-phosphaanthracenes allowed characterization of their fluorescence functionality and planar heteroanthracene frameworks. The crystal structures of 9-phosphaanthracenes are remarkably dependent on the aryl substituents at the 10 position; anthryl-substituted 9-phosphaanthracene showed unique polymorphs that induced different-colored crystals.

17.
Res Involv Engagem ; 3: 14, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29062539

RESUMO

PLAIN ENGLISH SUMMARY: Patients with rare diseases often help to develop new treatments for their conditions. But once developed, those treatments are sometimes priced too high for many patients to access them. We became aware that this is a problem in the course of a social science research project that examines the place of rare diseases in health policy. We therefore organized a two-day workshop to try and understand why this problem occurs and what might be done about it. The people who participated in our workshop were: representatives of rare disease patient organizations, experts in matters of drug regulation and assessment of new health technologies, consultants involved with companies producing treatments for rare diseases, and social scientists researching related issues. The main conclusions to emerge from the discussions were as follows: Problems of access to treatments for rare diseases are not just due to high prices; procedures for regulating, assessing and delivering new treatments also need to be better organized. Patients and patient organizations have much to contribute to this process. However, their resources are often very limited. Consequently, more needs to be done to help them use those resources as effectively as possible. In particular, regulators and healthcare providers need to ensure that their procedures are clear and efficiently managed, so as not to waste patient organizations' time and money. Clearer guidance is needed on what patient organizations can do to provide evidence of the effectiveness of new drugs. Insights gained in tackling rare diseases might also be applicable to common disorders. Finally, the consequences of Brexit for UK policies on rare diseases urgently need to be assessed. ABSTRACT: Since the enactment of orphan drug legislation in the USA, Europe and several other countries, an increasing number of treatments for rare diseases have been developed and many of them been approved for marketing. However, such treatments tend to be priced very high, and access to effective treatments remains a major challenge for patients with rare diseases - despite active involvement of patients and their support organizations in various stages of basic and applied research and commercial development. In order to allow patients to benefit from treatments proved effective for their diseases, we need to better understand why this challenge persists, and what steps might be taken to address it. To that end, we organized a policy-engagement workshop, bringing together individuals and organizations with direct experience of trying to secure access to a treatment for a rare disease along with individuals with relevant expertise in regulatory and commissioning processes for new medicines. With additional input from social scientists who offered different perspectives on the value of patient involvement, the workshop aimed to initiate a dialogue among the participants about how to address the challenge in a sustainable manner. Discussions at the workshop stressed that active involvement of patients is as valuable in the regulatory and commissioning processes as in the research and development of new medicines. However, it also highlighted certain risks and costs associated with such involvement. These include the costs of adjusting to abrupt changes in regulatory and commissioning processes, and the risk of being perceived as too close to commercial interests. To optimize use of scarce resources and ensure continuing active involvement, such risks and costs need to be better managed. Participants also noted that, owing to advances in genomic technologies, common diseases are also becoming divided into rare sub-categories, which are equally eligible for orphan drug designation. Consequently, involvement of wider patient communities beyond rare disease communities will be critical for continuing discussions about patients' involvement in regulatory and commissioning processes, and to consider how patients and their support organizations can best work with other stakeholders - including companies, regulators and policymakers - to ensure access to effective medicines.

18.
Chem Commun (Camb) ; 53(40): 5546-5548, 2017 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-28470296

RESUMO

Lithium 1,3-bis(2,6-diisopropylphenyl)-2,3-dihydro-1H-1,3,2-diazaborol-2-uide activates the C-F linkage of fluoroform (CF3H) and the Ruppert-Prakash reagent (CF3SiMe3) to provide difluoromethyl-substituted boranes as air-stable compounds.

19.
Org Lett ; 18(15): 3690-3, 2016 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-27442347

RESUMO

The palladium-catalyzed Negishi cross-coupling reaction of aryl iodides and bromides with (difluoromethyl)zinc reagent bearing a diamine such as TMEDA is achieved to provide the difluoromethylated aromatic compounds in good to excellent yields. The advantages of (difluoromethyl)zinc reagent are that (1) the derivatives, which possess different stability and reactivity, can be readily prepared via ligand screening and (2) transmetalation of a difluoromethyl group from the zinc reagent to palladium catalyst efficiently proceeds without an activator.

20.
Org Lett ; 18(15): 3686-9, 2016 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-27442584

RESUMO

The combination of difluoroiodomethane and zinc dust or diethylzinc can readily lead to (difluoromethyl)zinc reagents. Therefore, the first copper-catalyzed difluoromethylation of aryl iodides with the zinc reagents is accomplished to afford the difluoromethylated arenes. The reaction proceeds efficiently through the ligand/activator-free operation without addition of ligands for copper catalyst (e.g., phen and bpy) and activators for zinc reagent (e.g., KF, CsF, and NaO-t-Bu). Moreover, transmetalation of the CF2H group from zinc reagent to copper catalyst proceeds even at room temperature to form the cuprate [Cu(CF2H)2](-).

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