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1.
J Am Chem Soc ; 2024 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-39303271

RESUMO

Ketyl radicals are valuable reactive intermediates because they allow carbonyl chemistry to be extended beyond traditional electrophilic reactivity through simple single-electron reduction to a nucleophilic radical. However, this pathway is challenging due to the large negative reduction potentials of carbonyls, thus requiring highly reducing conditions. Herein, we describe the development of an alternative strategy to access ketyl radicals from aldehydes, which avoids the reduction pathway by instead proceeding via single-electron oxidation and desulfination of α-hydroxy sulfinates. These redox-active aldehyde adducts are generated in situ through the addition of sulfoxylate (SO22-) to aldehydes and possess low oxidation potentials, thereby facilitating ketyl radical formation and circumventing the need for strongly reducing conditions. We demonstrate the application of this sulfoxylate-mediated ketyl radical formation in ketyl-olefin coupling reactions.

2.
Angew Chem Int Ed Engl ; : e202413504, 2024 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-39140613

RESUMO

Asymmetric diboration of terminal alkenes is well established, and subsequent selective functionalization of the less hindered primary boronic ester is commonly achieved. Conversely, selective functionalization of the sterically less accessible secondary boronic ester remains challenging. An alternative way to control chemoselective functionalization of bis(boron) compounds is by engendering different Lewis acidity to the two boryl moieties, since reactivity would then be dictated by Lewis acidity instead of sterics. We report herein the regio- and enantioselective Pt-catalyzed diboration of unactivated alkenes with (pin)B-B(dan). A broad range of terminal and cyclic alkenes undergo diboration to furnish the differentiable 1,2-bis(boron) compounds with high levels of regio- and enantiocontrol, giving access to a wide variety of novel building blocks from a common intermediate. The reaction places the less Lewis acidic B(dan) group at the less hindered position and the resulting 1,2-bisboryl alkanes undergo selective transformations of the B(pin) group located at the more hindered position. The regioselectivity of diboration has been studied by DFT calculations and is believed to originate from the trans influence, which lowers the activation barrier for formation of the regioisomer that places the weaker electron donor [B(pin) vs B(dan)] opposite the strong electron donor (alkyl group) in the platinum complex.

3.
Health Soc Care Deliv Res ; 12(24): 1-158, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39206517

RESUMO

Background: Calls have been made for paramedics to have some form of care pathway that they could use to safely divert adults with epilepsy away from emergency departments and instigate ambulatory care improvements. Different configurations are possible. To know which to prioritise for implementation/evaluation, there is a need to determine which are acceptable to service users and likely National Health Service-feasible. Objective(s): (1) Identify configurations being considered, (2) understand service users' views of them and current provision, (3) identify what sort of care service users want and (4) determine which configuration(s) is considered to achieve optimal balance in meeting users' preference and being National Health Service-feasible. Design: Service providers were surveyed to address objective 1. Interviews with service users addressed objective 2. Objective 3 was addressed by completing discrete choice experiments. These determined users' care preferences for different seizure scenarios. Objective 4 was addressed by completing 'knowledge exchange' workshops. At these, stakeholders considered the findings on users' stated preferences and judged different pathway configurations against Michie's 'acceptability, practicability, effectiveness, affordability, side-effects and equity' feasibility criteria. Setting: This project took place in England. The survey recruited representatives from neurology and neuroscience centres and from urgent and emergency care providers. For the interviews, recruitment occurred via third-sector support groups. Recruitment for discrete choice experiments occurred via the North West Ambulance Service NHS Trust and public advert. Workshop participants were recruited from neurology and neuroscience centres, urgent and emergency care providers, support groups and commissioning networks. Participants: Seventy-two services completed the survey. Interviews were conducted with 25 adults with epilepsy (and 5 relatives) who had emergency service contact in the prior 12 months. Discrete choice experiments were completed by 427 adults with epilepsy (and 167 relatives) who had ambulance service contact in the prior 12 months. Workshops were completed with 27 stakeholders. Results: The survey identified a range of pathway configurations. They differed in where they would take the patient and their potential to instigate ambulatory care improvements. Users had been rarely consulted in designing them. The discrete choice experiments found that users want a configuration of care markedly different to that offered. Across the seizure scenarios, users wanted their paramedic to have access to their medical records; for an epilepsy specialist (e.g. an epilepsy nurse, neurologist) to be available to advise; for their general practitioner to receive a report; for the incident to generate an appointment with an epilepsy specialist; for the care episode to last < 6 hours; and there was a pattern of preference to avoid conveyance to emergency departments and stay where they were. Stakeholders judged this configuration to be National Health Service-feasible within 5-10 years, with some elements being immediately deployable. Limitations: The discrete choice experiment sample was broadly representative, but those reporting recent contact with an epilepsy specialist were over-represented. Conclusions: Users state they want a configuration of care that is markedly different to current provision. The configuration they prefer was, with support and investment, judged to likely be National Health Service-feasible. The preferred configuration should now be developed and evaluated to determine its actual deliverability and efficacy. Study registration: The study is registered as researchregistry4723. Funding: This award was funded by the National Institute for Health and Care Research (NIHR) Health and Social Care Delivery Research programme (NIHR award ref: 17/05/62) and is published in full in Health and Social Care Delivery Research; Vol. 12, No. 24. See the NIHR Funding and Awards website for further award information.


Ambulances often attend to people with epilepsy. Most of them are taken to the hospital's accident and emergency department. This typically has little benefit since most patients are already diagnosed and visit the accident and emergency department with non-emergency states. To change things, National Health Service organisations want an 'alternative care pathway' for paramedics to use. It could mean the person is not taken to the accident and emergency department but cared for elsewhere. Our project brought stakeholders together to develop an alternative care pathway that includes things important to patients and carers but is also National Health Service-feasible. Seventy National Health Service organisations first told us via a survey and a workshop which pathways they were considering and which might be feasible. Thirty people with epilepsy and their family members and friends were then interviewed. They explained what is wanted after a seizure and problems with current care. One problem was that going to the accident and emergency department does not lead to them getting a follow-up appointment with an epilepsy specialist to check their treatment is right. Using 'discrete choice experiments', around 430 people with epilepsy who recently contacted the ambulance service and 170 of their family and friends were asked to make a choice between alternative packages of care, to say which pathway they would prefer in different seizure situations. The results were clear. People wanted care different from what National Health Service organisations told us was available. The choice experiment showed everyone prefers pathways where paramedics have access to their medical records, an epilepsy specialist is available to advise the paramedic, the general practitioner gets a report and they get an appointment with an epilepsy specialist in the future. Everyone wants to avoid long episodes of care (6 hours) and after a typical seizure people with epilepsy want to stay at home. Three workshops were run with paramedics, epilepsy specialists and managers. They said the alternative care pathway wanted by users could be National Health Service-feasible. There is a need to implement and evaluate it now.


Assuntos
Serviço Hospitalar de Emergência , Epilepsia , Assistência Centrada no Paciente , Humanos , Epilepsia/terapia , Epilepsia/psicologia , Serviço Hospitalar de Emergência/estatística & dados numéricos , Adulto , Masculino , Feminino , Inglaterra , Inquéritos e Questionários , Pessoa de Meia-Idade , Comportamento de Escolha , Medicina Estatal , Preferência do Paciente , Pessoal Técnico de Saúde/psicologia , Entrevistas como Assunto
4.
Epilepsy Behav ; 158: 109936, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38970890

RESUMO

PURPOSE: With epilepsy increasingly affecting older adults, seizure-related care needs arise in new settings. Persons in these settings must receive optimal support and challenges identified for remediation. This may entail the epilepsy community researching in unfamiliar environments. One setting is care homes. Seizure-related ambulance incidents in them are common. We conducted the first qualitative study with care home staff to explore their experiences and challenges in managing suspected seizures. METHODS: Three online focus groups were organised for January 2024 to explore ambulance calls, post-incident procedures, and challenges faced by care home staff when managing seizures. Persons were eligible to participate if they worked as a care assistant, nurse or manager in a care home in North-West England. Different recruitment pathways were employed including direct approach, a managers' network, social media and a register of research interested homes. Focus group audio recordings were transcribed and analysed using Hamilton's Rapid Analysis. RESULTS: Recruitment was difficult; 13 care home staff from 12 different homes were ultimately recruited. Despite data saturation not being achieved, insights were gained regarding ambulance call decisions, paperwork navigation, and follow-up care challenges. Patients not having meaningful seizure action plans in place and regulatory restrictions were identified as factors that contributed to potentially avoidable calls for ambulance help being made. CONCLUSION: This study highlights systemic issues in care homes' seizure care, emphasizing the need for further research. The epilepsy community may need to innovate to better research within this increasingly important setting. This study offers insights into the effectiveness of different recruitment strategies.


Assuntos
Epilepsia , Grupos Focais , Convulsões , Humanos , Inglaterra , Epilepsia/terapia , Convulsões/terapia , Masculino , Feminino , Adulto , Pesquisa Qualitativa , Pessoal de Saúde/psicologia , Pessoa de Meia-Idade , Ambulâncias
5.
Angew Chem Int Ed Engl ; : e202410207, 2024 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-39038230

RESUMO

C(sp3)-rich heterocycles are privileged building blocks for pharmaceuticals and agrochemicals. Therefore, synthetic methods that provide access to novel saturated nitrogen-containing heterocycles are in high demand. Herein, we report a general synthesis of 1-azabicyclo[2.1.1]hexanes (1-aza-BCH) via a formal cycloaddition of azabicyclo[1.1.0]butanes (ABB) with styrenes under photochemical conditions. To overcome the challenging direct single electron reduction of ABBs, we designed a polar-radical-polar relay strategy that leverages a fast acid-mediated ring-opening of ABBs to form bromoazetidines, which undergo efficient debrominative radical formation to initiate the cycloaddition reaction. The reaction is applicable to a broad range of ABB-ketones and we demonstrate the 1-aza-BCH products can be further functionalised to access larger saturated, conformationally rigid heterocycles.

6.
J Am Chem Soc ; 146(20): 13719-13726, 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38721780

RESUMO

With increasing interest in constructing more three-dimensional entities, there has been growing interest in cross-coupling reactions that forge C(sp3)-C(sp3) bonds, which leads to additional challenges as it is not just a more difficult bond to construct but issues of stereocontrol also arise. Herein, we report the stereocontrolled cross-coupling of enantioenriched boronic esters with racemic allylic carbonates enabled by iridium catalysis, leading to the formation of C(sp3)-C(sp3) bonds with single or vicinal stereogenic centers. The method shows broad substrate scope, enabling primary, secondary, and even tertiary boronic esters to be employed, and can be used to prepare any of the four possible stereoisomers of a coupled product with vicinal chiral centers. The new method, which combines the simultaneous enantiospecific reaction of a chiral nucleophile with the enantioselective reaction of a chiral electrophile in a single process, offers a solution for stereodivergent cross-coupling of two C(sp3) fragments.

7.
Seizure ; 118: 17-27, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38613878

RESUMO

INTRODUCTION: Adults presenting to the ambulance service for diagnosed epilepsy are often transported to emergency departments (EDs) despite no clinical need. An alternative care pathway (CP) could allow paramedics to divert them from ED and instigate ambulatory care improvements. To identify the most promising CP configuration for subsequent testing, the COLLABORATE project surveyed people with epilepsy and family/friends who had recently used the English ambulance service to elicit preferences for 288 CP configurations for different seizures. This allowed CPs to be ranked according to alignment with service users' preferences. However, as well as being acceptable to users, a CP must be feasible. We thus engaged with paramedics, epilepsy specialists and commissioners to identify the optimal configuration. METHODS: Three Knowledge Exchange workshops completed. Participants considered COLLABORATE's evidence on service users' preferences for the different configurations. Nominal group techniques elicited views on the feasibility of users' preferences according to APEASE criteria. Workshop groups specified the configuration/s considered optimum. Qualitative data was analysed thematically. Utility to users of the specified CP configurations estimated using the COLLABORATE preference survey data. RESULTS: Twenty-seven participants found service users' preferences broadly feasible and outlined delivery recommendations. They identified enough commonality in preferences for different seizures to propose a single CP. Its configuration comprised: 1) patients staying where they were; 2) paramedics having access to medical records; 3) care episodes lasting <6 h; 4) paramedics receiving specialist advice on the day; 5) patient's GP being notified; and 6) a follow-up appointment being arranged with an epilepsy specialist. Preference data indicated higher utility for this configuration compared to current care. DISCUSSION: Stakeholders are of the view that the CP configuration favoured by service users could be NHS feasible. It should be developed and evaluated.


Assuntos
Ambulâncias , Epilepsia , Estudos de Viabilidade , Preferência do Paciente , Humanos , Adulto , Epilepsia/terapia , Feminino , Masculino , Serviços Médicos de Emergência , Pessoa de Meia-Idade , Assistência Ambulatorial , Serviço Hospitalar de Emergência
8.
Seizure ; 118: 28-37, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38615478

RESUMO

INTRODUCTION: To identify service users' preferences for an alternative care pathway for adults with epilepsy presenting to the ambulance service. METHODS: Extensive formative work (qualitative, survey and knowledge exchange) informed the design of a stated preference discrete choice experiment (DCE). This hypothetical survey was hosted online and consisted of 12 binary choices of alternative care pathways described in terms of: the paramedic's access to medical records/ 'care plan', what happens next (described in terms of conveyance), time, availability of epilepsy specialists today, general practitioner (GP) notification and future contact with epilepsy specialists. DCE scenarios were described as: (i) typical seizure at home. (ii) typical seizure in public, (iii) atypical seizure. Respondents were recruited by a regional English ambulance service and by national public adverts. Participants were randomised to complete 2 of the 3 DCEs. RESULTS: People with epilepsy (PWE; n = 427) and friends/family (n = 167) who completed the survey were representative of the target population. PWE preferred paramedics to have access to medical records, non-conveyance, to avoid lengthy episodes of care, availability of epilepsy specialists today, GP notification, and contact with epilepsy specialists within 2-3 weeks. Significant others (close family members or friends) preferred PWE experiencing an atypical seizure to be conveyed to an Urgent Treatment Centre and preferred shorter times. Optimal configuration of services from service users' perspective far out ranked current practice (rank 230/288 possible configurations). DISCUSSION: Preferences differ to current practice but have minimal variation by seizure type or stakeholder. Further work on feasibility of these pathways in England, and potentially beyond, is required.


Assuntos
Ambulâncias , Serviços Médicos de Emergência , Epilepsia , Humanos , Adulto , Masculino , Feminino , Pessoa de Meia-Idade , Epilepsia/terapia , Adulto Jovem , Preferência do Paciente/estatística & dados numéricos , Comportamento de Escolha/fisiologia , Adolescente , Idoso , Inquéritos e Questionários , Procedimentos Clínicos
9.
Epilepsy Behav ; 151: 109611, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38199055

RESUMO

PURPOSE: Suspected seizures present challenges for ambulance services, with paramedics reporting uncertainty over whether or not to convey individuals to emergency departments. The Risk of ADverse Outcomes after a Suspected Seizure (RADOSS) project aims to address this by developing a risk assessment tool utilizing structured patient care record and dispatch data. It proposes a tool that would provide estimates of an individual's likelihood of death and/or recontact with emergency care within 3 days if conveyed compared to not conveyed, and the likelihood of an 'avoidable attendance' occurring if conveyed. Knowledge Exchange workshops engaged stakeholders to resolve key design uncertainties before model derivation. METHOD: Six workshops involved 26 service users and their significant others (epilepsy or nonepileptic attack disorder), and 25 urgent and emergency care clinicians from different English ambulance regions. Utilizing Nominal Group Techniques, participants shared views of the proposed tool, benefits and concerns, suggested predictors, critiqued outcome measures, and expressed functionality preferences. Data were analysed using Hamilton's Rapid Analysis. RESULTS: Stakeholders supported tool development, proposing 10 structured variables for predictive testing. Emphasis was placed on the tool supporting, not dictating, care decisions. Participants highlighted some reasons why RADOSS might struggle to derive a predictive model based on structured data alone and suggested some non-structured variables for future testing. Feedback on prediction timeframes for service recontact was received, along with advice on amending the 'avoidable attendance' definition to prevent the tool's predictions being undermined by potential overuse of certain investigations in hospital. CONCLUSION: Collaborative stakeholder engagement provided crucial insights that can guide RADOSS to develop a user-aligned, optimized tool.


Assuntos
Serviços Médicos de Emergência , Humanos , Serviços Médicos de Emergência/métodos , Ambulâncias , Serviço Hospitalar de Emergência , Convulsões/diagnóstico , Convulsões/terapia , Medição de Risco
10.
BMC Emerg Med ; 23(1): 119, 2023 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-37807077

RESUMO

BACKGROUND: Paramedics convey a high proportion of seizure patients with no clinical need to emergency departments (EDs). In a landmark study, only 27% of UK paramedics reported being "Very…"/ "Extremely confident" making seizure conveyance decisions. Improved pre-registration education on seizures for paramedics is proposed. Clarity is needed on its potential given recent changes to how UK paramedics train (namely, degree, rather than brief vocational course). This study sought to describe UK student paramedics' perceived readiness to manage seizures and educational needs; compare this to what they report for other presentations; and, explore subgroup differences. METHODS: Six hundred thirty-eight students, in year 2 or beyond of their pre-registration programme completed a cross-sectional survey. They rated perceived confidence, knowledge, ability to care for, and educational needs for seizures, breathing problems and, headache. Primary measure was conveyance decision confidence. RESULTS: For seizures, 45.3% (95% CI 41.4-49.2) said they were "Very…"/"Extremely confident" to make conveyance decisions. This was similar to breathing problems, but higher than for headache (25.9%, 95% CI 22.6-29.5). Two hundred and thirty-nine participants (37.9%, 95% CI 34.1-41.8) said more seizure education was required - lower than for headache, but higher than for breathing problems. Subgroup differences included students on university-based programmes reporting more confidence for conveyance decisions than those completing degree level apprenticeships. CONCLUSIONS: Student paramedics report relatively high perceived readiness for managing seizures. Magnitude of benefit from enhancements to pre-registration education may be more limited than anticipated. Additional factors need attention if a sizeable reduction to unnecessary conveyances for seizures is to happen.


Assuntos
Serviços Médicos de Emergência , Paramédico , Humanos , Estudos Transversais , Convulsões/diagnóstico , Convulsões/terapia , Estudantes , Cefaleia , Reino Unido
11.
Angew Chem Int Ed Engl ; 62(50): e202312054, 2023 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-37877778

RESUMO

Enones are widely utilized linchpin functional groups in chemical synthesis and molecular biology. We herein report the direct conversion of boronic esters into enones using commercially available methoxyallene as a three-carbon building block. Following boronate complex formation by reaction of the boronic ester with lithiated-methoxyallene, protonation triggers a stereospecific 1,2-migration before oxidation generates the enone. The protocol shows broad substrate scope and complete enantiospecificity is observed with chiral migrating groups. In addition, various electrophiles could be used to induce 1,2-migration and give a much broader range of α-functionalized enones. Finally, the methodology was applied to a 14-step synthesis of the enone-containing polyketide 10-deoxymethynolide.

12.
J Am Chem Soc ; 145(33): 18649-18657, 2023 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-37552886

RESUMO

Carbon-phosphorus bond formation is significant in synthetic chemistry because phosphorus-containing compounds offer numerous indispensable biochemical roles. While there is a plethora of methods to access organophosphorus compounds, phosphonylations of readily accessible alkyl radicals to form aliphatic phosphonates are rare and not commonly used in synthesis. Herein, we introduce a novel phosphorus radical trap "BecaP" that enables facile and efficient phosphonylation of alkyl radicals under visible light photocatalytic conditions. Importantly, the ambiphilic nature of BecaP allows redox neutral reactions with both nucleophilic (activated by single-electron oxidation) and electrophilic (activated by single-electron reduction) alkyl radical precursors. Thus, a broad scope of feedstock alkyl potassium trifluoroborate salts and redox active carboxylate esters could be employed, with each class of substrate proceeding through a distinct mechanistic pathway. The mild conditions are applicable to the late-stage installation of phosphonate motifs into medicinal agents and natural products, which is showcased by the straightforward conversion of baclofen (muscle relaxant) to phaclofen (GABAB antagonist).

13.
J Am Chem Soc ; 145(30): 16508-16516, 2023 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-37471704

RESUMO

Enantioenriched organoboron intermediates are important building blocks in organic synthesis and drug discovery. Recently, transition metal-catalyzed enantioselective 1,2-metalate rearrangements of alkenylboronates have emerged as an attractive protocol to access these valuable reagents by installing two different carbon fragments across C═C π-bonds. Herein, we report the development of an iridium-catalyzed asymmetric allylation-induced 1,2-metalate rearrangement of bicyclo[1.1.0]butyl (BCB) boronate complexes enabled by strain release, which allows asymmetric difunctionalization of C-C σ-bonds, including dicarbonation and carboboration. This protocol provides a variety of enantioenriched three-dimensional 1,1,3-trisubstituted cyclobutane products bearing a boronic ester that can be readily derivatized. Notably, the reaction gives trans diastereoisomers that result from an anti-addition across the C-C σ-bond, which is in contrast to the syn-additions observed for reactions promoted by PdII-aryl complexes and other electrophiles in our previous works. The diastereoselectivity has been rationalized based on a combination of experimental data and density functional theory calculations, which suggest that the BCB boronate complexes are highly nucleophilic and react via early transition states with low activation barriers.

14.
Angew Chem Int Ed Engl ; 62(38): e202309684, 2023 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-37522816

RESUMO

Decarboxylative halogenation reactions of alkyl carboxylic acids are highly valuable reactions for the synthesis of structurally diverse alkyl halides. However, many reported protocols rely on stoichiometric strong oxidants or highly electrophilic halogenating agents. Herein, we describe visible-light photoredox-catalyzed decarboxylative halogenation reactions of N-hydroxyphthalimide-activated carboxylic acids that avoid stoichiometric oxidants and use inexpensive inorganic halide salts as the halogenating agents. Bromination with lithium bromide proceeds under simple, transition-metal-free conditions using an organic photoredox catalyst and no other additives, whereas dual photoredox-copper catalysis is required for chlorination with lithium chloride. The mild conditions display excellent functional-group tolerance, which is demonstrated through the transformation of a diverse range of structurally complex carboxylic acid containing natural products into the corresponding alkyl bromides and chlorides. In addition, we show the generality of the dual photoredox-copper-catalyzed decarboxylative functionalization with inorganic salts by extension to thiocyanation with potassium thiocyanide, which was applied to the synthesis of complex alkyl thiocyanates.

15.
J Am Chem Soc ; 145(28): 15207-15217, 2023 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-37410056

RESUMO

Borylations of inert carbon-hydrogen bonds are highly useful for transforming feedstock chemicals into versatile organoboron reagents. Catalysis of these reactions has historically relied on precious-metal complexes, which promote dehydrogenative borylations with diboron reagents under oxidant-free conditions. Recently, photoinduced radical-mediated borylations involving hydrogen atom transfer pathways have emerged as attractive alternatives because they provide complimentary regioselectivities and proceed under metal-free conditions. However, these net oxidative processes require stoichiometric oxidants and therefore cannot compete with the high atom economy of their precious-metal-catalyzed counterparts. Herein, we report that CuCl2 catalyzes radical-mediated, dehydrogenative C(sp3)-H borylations of alkanes with bis(catecholato)diboron under oxidant-free conditions. This is a result of an unexpected dual role of the copper catalyst, which promotes oxidation of the diboron reagent to generate an electrophilic bis-boryloxide that acts as an effective borylating agent in subsequent redox-neutral photocatalytic C-H borylations.

16.
Org Lett ; 25(2): 400-404, 2023 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-36626565

RESUMO

The identification of the beneficial pharmacokinetic properties of aza-spirocycles has led to the routine incorporation of these highly rigid and three-dimensional structures in pharmaceuticals. Herein, we report an operationally simple synthesis of spirocyclic dihydropyridines via an electrophile-induced dearomative semi-pinacol rearrangement of 4-(1'-hydroxycyclobutyl)pyridines. The various points for diversification of the spirocyclization precursors, as well as the synthetic utility of the amine and ketone functionalities in the products, provide the potential to rapidly assemble medicinally relevant spirocycles.

17.
Nat Chem ; 15(2): 248-256, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36424454

RESUMO

Polyketide natural products often contain common repeat motifs, for example, propionate, acetate and deoxypropionate, and so can be synthesized by iterative processes. We report here a highly efficient iterative strategy for the synthesis of polyacetates based on boronic ester homologation that does not require functional group manipulation between iterations. This process involves sequential asymmetric diboration of a terminal alkene, forming a 1,2-bis(boronic ester), followed by regio- and stereoselective homologation of the primary boronic ester with a butenyl metallated carbenoid to generate a 1,3-bis(boronic ester). Each transformation independently controls the stereochemical configuration, making the process highly versatile, and the sequence can be iterated prior to stereospecific oxidation of the 1,3-polyboronic ester to yield the 1,3-polyol. This methodology has been applied to a 14-step synthesis of the oxopolyene macrolide bahamaolide A, and the versatility of the 1,3-polyboronic esters has been demonstrated in various stereospecific transformations, leading to polyalkenes, -alkynes, -ketones and -aromatics with full stereocontrol.

18.
Epilepsy Behav ; 138: 108991, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36459813

RESUMO

OBJECTIVE: To identify the views of people with epilepsy (PWE), and their significant others, on the repurposing and trialing of statins as a potential antiepileptogenic or disease-modifying treatment for those who have had the first seizure. METHODS: Online questionnaire. Participants needed to be aged ≥ 16 years, UK residents, and able to independently complete a questionnaire in English. User groups distributed study adverts. Embedded infographics explained repurposing, why anti-seizure treatment is not typically started after a first seizure and the nature of randomized placebo-controlled trials (RCTs). The questionnaire asked participants to reflect and rate their expected willingness to have started an unspecified treatment after their first seizure/s (or that of the person with epilepsy they knew). They also rated willingness if the treatment were a statin, views of statins, the importance of an RCT of statins to their community, the outcomes it should assess, and their willingness to have taken part in it. The estimated number needed for the survey was 324. RESULTS: Responses from 213 persons were analyzed; 111 (52.1%) were PWE and 102 (47.9%) significant others. The median years diagnosed was 10 and PWE suffered from relatively severe epilepsy. One hundred and seventeen (54.9%) said they would have started an unspecified treatment after their first seizure/s (or supported the person with epilepsy they knew to have). A similar proportion (55.4%) said they would have started the treatment if it were a statin. Participants' main concern about statins, expressed by 79%, was their possible side effects. Repurposing was a concern for only 25%. Most (85.8%) rated an RCT of statins as of extreme or high importance; 54.4% said they would have participated. CONCLUSION: The PWE and significant others (SOs) responding to our survey expressed views towards repurposing statins that were generally positive and indicate a trial in those who have had a first seizure might be feasible. Concerns regarding side effects are common. Our findings could help optimize a future trial's design and the case for funding. Limitations include that we did not survey persons who had experienced a first seizure and did not go on to develop epilepsy. Also, persons with uncontrolled epilepsy were overrepresented.


Assuntos
Epilepsia , Inibidores de Hidroximetilglutaril-CoA Redutases , Humanos , Anticonvulsivantes/uso terapêutico , Epilepsia/tratamento farmacológico , Epilepsia/induzido quimicamente , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Inquéritos e Questionários , Reino Unido , Ensaios Clínicos Controlados Aleatórios como Assunto
19.
Angew Chem Int Ed Engl ; 62(7): e202217064, 2023 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-36507714

RESUMO

The development of preparative methods for the synthesis of four-membered carbocycles is gaining increasing importance due to the widespread utility of cyclic compounds in medicinal chemistry. Herein, we report the development of a new methodology for the production of spirocyclic epoxides and aziridines containing a cyclobutane motif. In a two-step one-pot process, a bicyclo[1.1.0]butyl sulfoxide is lithiated and added to a ketone, aldehyde or imine, and the resulting intermediate is cross-coupled with an aryl triflate through C-C σ-bond alkoxy- or aminopalladation with concomitant epoxide or aziridine formation. After careful optimization, a remarkably efficient reaction was conceived that tolerated a broad variety of both aromatic and aliphatic substrates. Lastly, through several high yielding ring-opening reactions, we demonstrated the excellent applicability of the products as modular building blocks for the introduction of three-dimensional structures into target molecules.

20.
Angew Chem Weinheim Bergstr Ger ; 135(7): e202217064, 2023 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-38516047

RESUMO

The development of preparative methods for the synthesis of four-membered carbocycles is gaining increasing importance due to the widespread utility of cyclic compounds in medicinal chemistry. Herein, we report the development of a new methodology for the production of spirocyclic epoxides and aziridines containing a cyclobutane motif. In a two-step one-pot process, a bicyclo[1.1.0]butyl sulfoxide is lithiated and added to a ketone, aldehyde or imine, and the resulting intermediate is cross-coupled with an aryl triflate through C-C σ-bond alkoxy- or aminopalladation with concomitant epoxide or aziridine formation. After careful optimization, a remarkably efficient reaction was conceived that tolerated a broad variety of both aromatic and aliphatic substrates. Lastly, through several high yielding ring-opening reactions, we demonstrated the excellent applicability of the products as modular building blocks for the introduction of three-dimensional structures into target molecules.

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