Asymmetric synthesis of tri- and tetrasubstituted trifluoromethyl dihydropyranones from alpha-aroyloxyaldehydes via NHC redox catalysis

We thank the Royal Society for a University Research Fellowship (A.D.S.), and the European Research Council under the European Union’s Seventh Framework Programme (FP7/2007-2013) ERC Grant Agreement No. 279850 (A.T.D.).The asymmetric synthesis of tri- and tetrasubstituted trifluoromethyl dihydropyranones via an NHC-catalyzed redox process, introducing methyl, benzyl, and aryl substituents to the C(5) position, is presented. Their substrate-controlled derivatization into δ-lactones and cyclic hemiacetals containing stereogenic trifluoromethyl groups is also described.PostprintPeer reviewe

Enantioselective NHC-catalyzed redox [2+2] cycloadditions with perfluoroketones; a route to fluorinated oxetanes

The authors thank the Royal Society for a University Research Fellowship (A.D.S.), and the European Research Council under the European Union's Seventh Framework Programme (FP7/2007-2013) ERC grant agreement no. 279850 (A.T.D.).The N-heterocyclic carbene (NHC) catalyzed redox formal [2+2] cycloaddition between α-aroyloxyaldehydes and perfluoroketones, followed by ring-opening in situ delivers a variety of perfluorinated β-hydroxycarbonyl compounds in good yield, and excellent diastereo- and enantioselectivity. Through a reductive work-up and subsequent cyclization, this protocol offers access to highly substituted fluorinated oxetanes in two steps and in high ee.PostprintPeer reviewe

NHC-catalyzed enantioselective synthesis of β-trifluoromethyl-β-hydroxyamides

Authors acknowlege the European Research Council under the European Union’s Seventh Framework Programme (FP7/2007-2013) ERC grant agreement no. 279850 (A.T.D.). We also thank the EPSRC UK National Mass Spectrometry Facility at Swansea University.The N-heterocyclic carbene (NHC) catalyzed formal [2+2] cycloaddition between α-aroyloxyaldehydes and trifluoroacetophenones, followed by ring-opening with an amine or reducing agent is described. The resulting β-hydroxy-β-trifluoromethyl amide and alcohol products are produced with reasonable diastereocontrol (typically ~70:30 dr) and excellent enantioselectivity, and can be isolated in moderate to good yield as a single diastereoisomer.Publisher PDFPeer reviewe

Enantioselective NHC-catalysed redox [4+2]-hetero-Diels-Alder reactions using α-aroyloxyaldehydes and unsaturated ketoesters

The authors thank the European Research Council under the European Union’s Seventh Framework Programme (FP7/2007-2013) ERC Grant Agreement No. 279850 (J.E.T. and A.T.D.) as well as the EPSRC, UK and AstraZeneca plc, UK (Case award to J.J.D.) for financial support. A.D.S. thanks the Royal Society, London, UK, for a Wolfson Merit Award.N-Heterocyclic carbene (NHC)-catalysed redox [4+2]-hetero-Diels-Alder reactions of α-aroyloxyaldehydes with either β,γ-unsaturated α-ketoesters or α,β-unsaturated γ-ketoesters generates substituted syn-dihydropyranones in good yield with excellent enantioselectivity (up to >99:1 er). The product diastereoselectivity is markedly dependent upon the nature of the unsaturated enone substituent. The presence of either electron-neutral or electron-rich aryl substituents gives excellent diastereoselectivity (up to >99:5 dr), while electron-deficient aryl substituents give reduced diastereoselectivity. In these cases, the syn-dihydropyranone products are more susceptible to base-promoted epimerisation at the C(4)-position under the reaction conditions, accounting for the lower diastereoselectivity obtained.PostprintPeer reviewe

Effect of Theophylline as Adjunct to Inhaled Corticosteroids on Exacerbations in Patients With COPD: A Randomized Clinical Trial

Importance: Chronic obstructive pulmonary disease (COPD) is a major global health issue and theophylline is used extensively. Preclinical investigations have demonstrated that low plasma concentrations (1-5 mg/L) of theophylline enhance antiinflammatory effects of corticosteroids in COPD.  Objective: To investigate the effectiveness of adding low-dose theophylline to inhaled corticosteroids in COPD.  Design, Setting, and Participants: The TWICS (theophylline with inhaled corticosteroids) trial was a pragmatic, double-blind, placebo-controlled, randomized clinical trial that enrolled patients with COPD between February 6, 2014, and August 31, 2016. Final follow-up ended on August 31, 2017. Participants had a ratio of forced expiratory volume in the first second to forced vital capacity (FEV1/FVC) of less than 0.7 with at least 2 exacerbations (treated with antibiotics, oral corticosteroids, or both) in the previous year and were using an inhaled corticosteroid. This study included 1578 participants in 121 UK primary and secondary care sites.  Interventions: Participants were randomized to receive low-dose theophylline (200 mg once or twice per day) to provide plasma concentrations of 1 to 5 mg/L (determined by ideal body weight and smoking status) (n = 791) or placebo (n = 787).  Main Outcomes and Measures: The number of participant-reported moderate or severe exacerbations treated with antibiotics, oral corticosteroids, or both over the 1-year treatment period.  Results: Of the 1567 participants analyzed, mean (SD) age was 68.4 (8.4) years and 54% (843) were men. Data for evaluation of the primary outcome were available for 1536 participants (98%) (772 in the theophylline group; 764 in the placebo group). In total, there were 3430 exacerbations: 1727 in the theophylline group (mean, 2.24 [95% CI, 2.10-2.38] exacerbations per year) vs 1703 in the placebo group (mean, 2.23 [95% CI, 2.09-2.37] exacerbations per year); unadjusted mean difference, 0.01 (95% CI, −0.19 to 0.21) and adjusted incidence rate ratio, 0.99 (95% CI, 0.91-1.08). Serious adverse events in the theophylline and placebo groups included cardiac, 2.4% vs 3.4%; gastrointestinal, 2.7% vs 1.3%; and adverse reactions such as nausea (10.9% vs 7.9%) and headaches (9.0% vs 7.9%).  Conclusions and Relevance: Among adults with COPD at high risk of exacerbation treated with inhaled corticosteroids, the addition of low-dose theophylline, compared with placebo, did not reduce the number COPD exacerbations over a 1-year period. The findings do not support the use of low-dose theophylline as adjunctive therapy to inhaled corticosteroids for the prevention of COPD exacerbations

Low-dose oral theophylline combined with inhaled corticosteroids for people with chronic obstructive pulmonary disease and high risk of exacerbations: a RCT

BACKGROUND: Despite widespread use of therapies such as inhaled corticosteroids (ICSs), people with chronic obstructive pulmonary disease (COPD) continue to suffer, have reduced life expectancy and utilise considerable NHS resources. Laboratory investigations have demonstrated that at low plasma concentrations (1-5 mg/l) theophylline markedly enhances the anti-inflammatory effects of corticosteroids in COPD. OBJECTIVE: To determine the clinical effectiveness and cost-effectiveness of adding low-dose theophylline to a drug regimen containing ICSs in people with COPD at high risk of exacerbation. DESIGN: A multicentre, pragmatic, double-blind, randomised, placebo-controlled clinical trial. SETTING: The trial was conducted in 121 UK primary and secondary care sites. PARTICIPANTS: People with COPD [i.e. who have a forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC) of < 0.7] currently on a drug regimen including ICSs with a history of two or more exacerbations treated with antibiotics and/or oral corticosteroids (OCSs) in the previous year. INTERVENTIONS: Participants were randomised (1 : 1) to receive either low-dose theophylline or placebo for 1 year. The dose of theophylline (200 mg once or twice a day) was determined by ideal body weight and smoking status. PRIMARY OUTCOME: The number of participant-reported exacerbations in the 1-year treatment period that were treated with antibiotics and/or OCSs. RESULTS: A total of 1578 people were randomised (60% from primary care): 791 to theophylline and 787 to placebo. There were 11 post-randomisation exclusions. Trial medication was prescribed to 1567 participants: 788 in the theophylline arm and 779 in the placebo arm. Participants in the trial arms were well balanced in terms of characteristics. The mean age was 68.4 [standard deviation (SD) 8.4] years, 54% were male, 32% smoked and mean FEV1 was 51.7% (SD 20.0%) predicted. Primary outcome data were available for 98% of participants: 772 in the theophylline arm and 764 in the placebo arm. There were 1489 person-years of follow-up data. The mean number of exacerbations was 2.24 (SD 1.99) for participants allocated to theophylline and 2.23 (SD 1.97) for participants allocated to placebo [adjusted incidence rate ratio (IRR) 0.99, 95% confidence interval (CI) 0.91 to 1.08]. Low-dose theophylline had no significant effects on lung function (i.e. FEV1), incidence of pneumonia, mortality, breathlessness or measures of quality of life or disease impact. Hospital admissions due to COPD exacerbation were less frequent with low-dose theophylline (adjusted IRR 0.72, 95% CI 0.55 to 0.94). However, 39 of the 51 excess hospital admissions in the placebo group were accounted for by 10 participants having three or more exacerbations. There were no differences in the reporting of theophylline side effects between the theophylline and placebo arms. LIMITATIONS: A higher than expected percentage of participants (26%) ceased trial medication; this was balanced between the theophylline and placebo arms and mitigated by over-recruitment (n = 154 additional participants were recruited) and the high rate of follow-up. The limitation of not using documented exacerbations is addressed by evidence that patient recall is highly reliable and the results of a small within-trial validation study. CONCLUSION: For people with COPD at high risk of exacerbation, the addition of low-dose oral theophylline to a drug regimen that includes ICSs confers no overall clinical or health economic benefit. This result was evident from the intention-to-treat and per-protocol analyses. FUTURE WORK: To promote consideration of the findings of this trial in national and international COPD guidelines. TRIAL REGISTRATION: Current Controlled Trials ISRCTN27066620. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 23, No. 37. See the NIHR Journals Library website for further project information

Use of low-dose oral theophylline as an adjunct to inhaled corticosteroids in preventing exacerbations of chronic obstructive pulmonary disease: study protocol for a randomised controlled trial.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is associated with high morbidity, mortality, and health-care costs. An incomplete response to the anti-inflammatory effects of inhaled corticosteroids is present in COPD. Preclinical work indicates that 'low dose' theophylline improves steroid responsiveness. The Theophylline With Inhaled Corticosteroids (TWICS) trial investigates whether the addition of 'low dose' theophylline to inhaled corticosteroids has clinical and cost-effective benefits in COPD. METHOD/DESIGN: TWICS is a randomised double-blind placebo-controlled trial conducted in primary and secondary care sites in the UK. The inclusion criteria are the following: an established predominant respiratory diagnosis of COPD (post-bronchodilator forced expiratory volume in first second/forced vital capacity [FEV1/FVC] of less than 0.7), age of at least 40 years, smoking history of at least 10 pack-years, current inhaled corticosteroid use, and history of at least two exacerbations requiring treatment with antibiotics or oral corticosteroids in the previous year. A computerised randomisation system will stratify 1424 participants by region and recruitment setting (primary and secondary) and then randomly assign with equal probability to intervention or control arms. Participants will receive either 'low dose' theophylline (Uniphyllin MR 200 mg tablets) or placebo for 52 weeks. Dosing is based on pharmacokinetic modelling to achieve a steady-state serum theophylline of 1-5 mg/l. A dose of theophylline MR 200 mg once daily (or placebo once daily) will be taken by participants who do not smoke or participants who smoke but have an ideal body weight (IBW) of not more than 60 kg. A dose of theophylline MR 200 mg twice daily (or placebo twice daily) will be taken by participants who smoke and have an IBW of more than 60 kg. Participants will be reviewed at recruitment and after 6 and 12 months. The primary outcome is the total number of participant-reported COPD exacerbations requiring oral corticosteroids or antibiotics during the 52-week treatment period. DISCUSSION: The demonstration that 'low dose' theophylline increases the efficacy of inhaled corticosteroids in COPD by reducing the incidence of exacerbations is relevant not only to patients and clinicians but also to health-care providers, both in the UK and globally. TRIAL REGISTRATION: Current Controlled Trials ISRCTN27066620 was registered on Sept. 19, 2013, and the first subject was randomly assigned on Feb. 6, 2014

Direct Copper-Catalyzed Three-Component Synthesis of Sulfonamides

First introduced into medicines in the 1930s, the sulfonamide functional group continues to be present in a wide range of contemporary pharmaceuticals and agrochemicals. Despite their popularity in the design of modern bioactive molecules, the underpinning methods for sulfonamide synthesis are essentially unchanged since their introduction, and rely on the use of starting materials with preinstalled sulfur-functionality. Herein we report a direct single-step synthesis of sulfonamides that combines two of the largest monomer sets available in discovery chemistry, (hetero)­aryl boronic acids and amines, along with sulfur dioxide, using a Cu­(II) catalyst, to deliver a broad range of sulfonamides. Sulfur dioxide is provided by the surrogate reagent DABSO. The reaction tolerates broad variation in both coupling partners, including aryl, heteroaryl and alkenyl boronic acids, as well as cyclic and acyclic alkyl secondary amines, and primary anilines. We validate the method by showing that a variety of drugs, and drug-fragments, can be incorporated into the process