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1.
Chemistry ; 30(30): e202400708, 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38529695

RESUMO

The synthesis of group 4 metal 1-metallacyclobuta-2,3-dienes as organometallic analogues of elusive 1,2-cyclobutadiene has so far been limited to SiMe3 substituted examples. We present the synthesis of two Ph substituted dilithiated ligand precursors for the preparation of four new 1-metallacyclobuta-2,3-dienes [rac-(ebthi)M] (M=Ti, Zr; ebthi=1,2-ethylene-1,10-bis(η5-tetrahydroindenyl)). The organolithium compounds [Li2(RC3Ph)] (1 b: R=Ph, 1 c: R=SiMe3) as well as the metallacycles of the general formula [rac-(ebthi)M(R1C3R2)] (2 b: M=Ti, R1=R2=Ph, 2 c: M=Ti, R1=Ph, R2=SiMe3; 3 b: M=Zr, R1=R2=Ph; 3 c: M=Zr, R1=Ph, R2=SiMe3) were fully characterised. Single crystal X-ray diffraction and quantum chemical bond analysis of the Ti and Zr complexes reveal ligand influence on the biradicaloid character of the titanocene complexes. X-band EPR spectroscopy of structurally similar Ti complexes [rac-(ebthi)Ti(Me3SiC3SiMe3)] (2 a), 2 b, and 2 c was carried out to evaluate the accessibility of an EPR active triplet state. Cyclic voltammetry shows that introduction of Ph groups renders the complexes easier to reduce. 13C CPMAS NMR analysis provides insights into the cause of the low field shift of the resonances of metal-bonded carbon atoms and provides evidence of the absence of the ß-C-Ti interaction.

2.
Nat Commun ; 14(1): 3726, 2023 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-37349304

RESUMO

The development of alternative clean energy carriers is a key challenge for our society. Carbon-based hydrogen storage materials are well-suited to undergo reversible (de)hydrogenation reactions and the development of catalysts for the individual process steps is crucial. In the current state, noble metal-based catalysts still dominate this field. Here, a system for partially reversible and carbon-neutral hydrogen storage and release is reported. It is based on the dual-functional roles of formamides and uses a small molecule Fe-pincer complex as the catalyst, showing good stability and reusability with high productivity. Starting from formamides, quantitative production of CO-free hydrogen is achieved at high selectivity ( > 99.9%). This system works at modest temperatures of 90 °C, which can be easily supplied by the waste heat from e.g., proton-exchange membrane fuel cells. Employing such system, we achieve >70% H2 evolution efficiency and >99% H2 selectivity in 10 charge-discharge cycles, avoiding undesired carbon emission between cycles.


Assuntos
Formamidas , Hidrogênio , Prótons , Hidrogenação , Catálise
3.
ACS Cent Sci ; 8(10): 1457-1463, 2022 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-36313168

RESUMO

We report here a feasible hydrogen storage and release process by interconversion of readily available (bi)carbonate and formate salts in the presence of naturally occurring α-amino acids. These transformations are of interest for the concept of a circular carbon economy. The use of inorganic carbonate salts for hydrogen storage and release is also described for the first time. Hydrogenation of these substrates proceeds with high formate yields in the presence of specific manganese pincer catalysts and glutamic acid. Based on this, cyclic hydrogen storage and release processes with carbonate salts succeed with good H2 yields.

4.
Chemistry ; 27(17): 5546-5554, 2021 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-33624911

RESUMO

Direct arylation of most five-membered ring heterocycles are generally easily accessible and strongly favored at the α-position using classical palladium-catalysis. Conversely, regioselective functionalization of such heterocycles at the concurrent ß-position remains currently very challenging. Herein, we report general conditions for regioselective direct arylation at the ß-position of pyrazoles, while C-H α-position is free. By using aryl bromides as the aryl source and a judicious choice of solvent, the arylation reaction of variously N-substituted pyrazoles simply proceeds via ß-C-H bond functionalization. The ß-regioselectivity is promoted by a ligand-free palladium catalyst and a simple base without oxidant or further additive, and tolerates a variety of substituents on the bromoarene. DFT calculations revealed that a protic solvent such as 2-ethoxyethan-1-ol significantly enhances the acidity of the proton at ß-position of the pyrazoles and thus favors this direct ß-C-H bond arylation. This selective pyrazoles ß-C-H bond arylation was successfully applied for the straightforward building of π-extended poly(hetero)aromatic structures via further Pd-catalyzed combined α-C-H intermolecular and intramolecular C-H bond arylation in an overall highly atom-economical process.

5.
Chem Rec ; 21(2): 343-356, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33332755

RESUMO

The direct functionalization of two different C-H bonds of the same organic molecule using different procedures - also called regiodivergent C-H bond functionalization - currently represents an important research topic in organic chemistry, as it demonstrates the versatility of C-H bond functionalization methodology. Over the last decade, the number of tools to control such regiodivergent C-H bond functionalizations has increased significantly. In this account, we will present the various tools that allowed us to arylate different positions of various (hetero)arenes, via a C-H bond functionalization, using palladium or ruthenium catalysis.

6.
Chem Sci ; 12(48): 16074-16084, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-35024129

RESUMO

The structure, bonding, and reactivity of small, highly unsaturated ring systems is of fundamental interest for inorganic and organic chemistry. Four-membered metallacyclobuta-2,3-dienes, also referred to as metallacycloallenes, are among the most exotic examples for ring systems as these represent organometallic analogs of 1,2-cyclobutadiene, the smallest cyclic allene. Herein, the synthesis of the first examples of 1-zirconacyclobuta-2,3-dienes of the type [Cp'2Zr(Me3SiC3SiMe3)] (Cp'2 = rac-(ebthi), (ebthi = 1,2-ethylene-1,1'-bis(η5-tetrahydroindenyl)) (2a); rac-Me2Si(thi)2, thi = (η5-tetrahydroindenyl), (2b)) is presented. Both complexes undergo selective thermal C-H activation at the 7-position of the ansa-cyclopentadienyl ligand to produce a new type of "tucked-in" zirconocene system, 3a and 3b, that possesses a η3-propargyl/allenyl ligand. Both types of complexes react with carbonyl compounds, producing enynes in the case of 2a and 2b, as well as η1-allenyl complexes for 3a and 3b. Computational analysis of the structure and bonding of 2a and 3a reveals significant differences to a previously described related Ti complex. All complexes were fully characterised, including X-ray crystallography and experimental results were supported by DFT analysis.

7.
Can J Surg ; 63(2): E174-E180, 2020 04 17.
Artigo em Inglês | MEDLINE | ID: mdl-32302084

RESUMO

Background: Hospital readmissions after bariatric surgery can significantly increase health care costs. Rates of readmission after bariatric surgery have ranged from 0.6% to 11.3%, but the rate of complications and the factors that predict readmission have not been well characterized in Canada. The objective of this study was to characterize readmission rates and the factors that predict 30-day readmission in a Canadian centre. Methods: A retrospective study was performed on all patients who underwent bariatric surgery between 2010 and 2015 in a single Canadian centre. Procedures included laparoscopic Roux-en-Y gastric bypass (LRYGB), laparoscopic sleeve gastrectomy (LSG) and laparoscopic adjustable gastric banding (LAGB). Prospectively collected data were extracted from an administrative database. Multivariable logistic regression analysis was performed to determine which factors predict 30-day readmission. Results: A total of 1468 patients had bariatric surgery (51.0% LRYGB, 40.5% LSG, 8.6% LAGB) during the 6-year study period, with an overall 30-day readmission rate of 7.5%. LRYGB was associated with a higher readmission rate (11.4%) than LSG (3.7%) or LAGB (1.6%). Common reasons for readmission were infection (24.8%), pain (17.4%) and nausea or vomiting (10.1%). Multivariable analysis identified 3 factors that independently predicted readmission: length of stay greater than 4 days (odds ratio [OR] 2.18, 95% confidence interval [CI] 1.03-4.63, p = 0.042), LRYGB (OR 5.21, 95% CI 1.19-22.73, p = 0.028) and acute renal failure (OR 14.10, 95% CI 1.07-186.29, p = 0.045). Conclusion: Readmissions after bariatric surgery were most commonly caused by potentially preventable factors, such as pain, nausea or vomiting. Strategies to identify and address factors associated with readmission may reduce readmissions and health care costs after bariatric surgery in a publicly funded health care system.


Contexte: Les réadmissions hospitalières après la chirurgie bariatrique peuvent accroître significativement le coût des soins de santé. Les taux de ces réadmissions ont varié de 0,6 % à 11,3 %, mais le taux de complications et les facteurs de prédiction des réadmissions n'ont pas été bien caractérisés au Canada. L'objectif de cette étude est de caractériser les taux de réadmissions et les facteurs qui permettent de prédire une réadmission à 30 jours dans un centre canadien. Méthodes: Nous avons étudié rétrospectivement tous les cas de chirurgie bariatrique effectués entre 2010 et 2015 dans un établissement canadien. Les interventions incluaient la dérivation gastrique Roux-en-Y laparoscopique (DGRYL), la gastrectomie en manchon laparoscopique (GML) et la gastroplastie laparoscopique avec anneau ajustable (GLAA). Les données recueillies de manière prospective ont été extraites d'une base de données administrative. Nous avons procédé à une analyse de régression logistique multivariée pour déterminer quels facteurs permettaient de prédire la réadmission à 30 jours. Résultats: En tout, 1468 patients ont subi une chirurgie bariatrique (51,0 % DGRYL, 40,5 % GML et 8,6 % GLAA) durant les 6 années de l'étude, avec un taux global de réadmission à 30 jours de 7,5 %. La DGRYL a été associée un taux de réadmission plus élevé (11,4 %) que la GML (3,7 %) ou la GLAA (1,6 %). Les raisons de réadmission les plus fréquentes ont été infection (24,8 %), douleur (17,4 %) et nausées ou vomissements (10,1 %). L'analyse multivariée a permis de dégager 3 facteurs indépendants de réadmission, soit séjour de plus de 4 jours (rapport des cotes [RR] 2,18, intervalle de confiance [IC] de 95 % 1,03­4,63, p = 0,042), DGRYL (RC 5,21, IC de 95 % 1,19­22,73, p = 0,028) et insuffisance rénale aiguë (RC 14,10, IC de 95 % 1,07­186,29, p = 0,045). Conclusion: Les réadmissions après la chirurgie bariatrique ont le plus souvent été dues à des facteurs évitables, tels que douleur, nausées et vomissements. Des stratégies visant à identifier et à corriger les facteurs de réadmission pourraient réduire ces dernières et le coût des soins de santé après la chirurgie bariatrique dans un système de santé public.


Assuntos
Cirurgia Bariátrica , Readmissão do Paciente/estatística & dados numéricos , Complicações Pós-Operatórias/epidemiologia , Injúria Renal Aguda/epidemiologia , Adulto , Alberta/epidemiologia , Feminino , Humanos , Tempo de Internação/estatística & dados numéricos , Masculino , Análise Multivariada , Estudos Retrospectivos
8.
Can J Surg ; 63(2): E123-E128, 2020 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-32195557

RESUMO

Background: Idiopathic intracranial hypertension (IIH) is a rare condition typically affecting women with obesity who are of child-bearing age. Patients commonly present with headaches, visual disturbances, pulsatile tinnitus and papilledema. The association between IIH and obesity has been well established in the literature, suggesting that weight loss may contribute to improving IIH. For patients with severe obesity for whom conservative management is not successful, bariatric surgery is an effective modality for weight loss. We aimed to systematically review the literature to determine the efficacy of bariatric surgery in the treatment of IIH Methods: We conducted a comprehensive search of MEDLINE, Embase, Scopus, the Cochrane Library and Web of Science (limited to studies in humans published in English between January 1946 and July 2015). Results: Twelve primary studies (n = 39 patients) were included in the systematic review. All patients had a preoperative diagnosis of IIH. Preoperative body mass index (BMI) was 47.4 ± 3.6 kg/m2 ; BMI improved to 33.7 ± 2.1 kg/m2 and 33.9 ± 11.6 kg/m2 at 6 and 12 months postoperatively, respectively. Lumbar puncture opening pressures decreased from 34.4 ± 6.9 cmH2O to 14.0 ± 3.6 cmH2O after surgery. Common symptoms of IIH improved after bariatric surgery: headaches (100% preoperatively v. 10% postoperatively), visual complaints (62% v. 44%), tinnitus (56% v. 3%) and papilledema (62% v. 8%). Conclusion: Bariatric surgery appears to lead to considerable improvement in IIH. Idiopathic intracranial hypertension is not a well-publicized comorbidity of obesity, but its presence may be considered as an indication for bariatric surgery.


Contexte: L'hypertension intracrânienne (HTIC) idiopathique est une affection rare qui touche surtout les femmes atteintes d'obésité en âge de procréer. Les symptômes courants sont des maux de tête, des troubles de la vue, des acouphènes pulsatiles et un oedème papillaire. Le lien entre l'HTIC idiopathique et l'obésité est bien établi dans la littérature, ce qui suggère que la perte de poids pourrait améliorer le tableau clinique de l'HTIC. Pour les patients atteints d'obésité sévère pour lesquels le traitement conservateur ne fonctionne pas, la chirurgie bariatrique est un moyen efficace de perdre du poids. Cette revue systématique de la littérature vise à déterminer l'efficacité de la chirurgie bariatrique dans le traitement de l'HTIC idiopathique. Méthodes: Nous avons interrogé MEDLINE, Embase, Scopus, la Bibliothèque Cochrane et Web of Science (limites : études portant sur les humains publiées en anglais entre janvier 1946 et juillet 2015). Résultats: Douze études primaires (n = 39 patients) ont été incluses dans la revue systématique. Tous les patients avaient un diagnostic préopératoire d'HTIC idiopathique. L'indice de masse corporelle (IMC) préopératoire était de 47,4 ± 3,6 kg/m2 ; l'IMC est passé à 33,7 ± 2,1 kg/m2 6 mois après l'opération, puis à 33,9 ± 11,6 kg/m2 12 mois après l'opération. Les pressions d'ouverture des ponctions lombaires sont passées de 34,4 ± 6,9 cmH2O à 14,0 ± 3,6 cmH2O après l'opération. Les symptômes courants de l'HTIC idiopathique se sont améliorés après la chirurgie bariatrique : maux de tête (100% avant opération c. 10% après), troubles de la vue (62% c. 44%), acouphènes pulsatiles (56% c. 3%) et œdème papillaire (62% c. 8%). Conclusion: La chirurgie bariatrique semble améliorer considérablement les symptômes d'HTIC idiopathique. Cette affection n'est pas une comorbidité bien connue de l'obésité, mais sa présence peut être une indication pour la chirurgie bariatrique comme traitement.


Assuntos
Cirurgia Bariátrica , Obesidade/complicações , Pseudotumor Cerebral/cirurgia , Índice de Massa Corporal , Cefaleia/etiologia , Cefaleia/cirurgia , Humanos , Obesidade/cirurgia , Papiledema/etiologia , Papiledema/cirurgia , Pseudotumor Cerebral/etiologia , Zumbido/etiologia , Zumbido/cirurgia , Transtornos da Visão/etiologia , Transtornos da Visão/cirurgia
9.
Can J Surg ; 62(5): 315-319, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31550092

RESUMO

Background: Bariatric surgery has been shown to induce type 2 diabetes mellitus (T2DM) remission in severely obese patients. After laparoscopic Roux-en-Y gastric bypass (LRYGB), diabetes remission occurs early and independently of weight loss. Previous research has identified preoperative factors for remission, such as duration of diabetes and HbA1c. Understanding factors that predict diabetes remission can help to select patients who will benefit most from bariatric surgery. Methods: We retrospectively reviewed all T2DM patients who underwent laparoscopic sleeve gastrectomy (LSG) or LRYGB between January 2008 and July 2014. The primary outcome was diabetes remission, defined as the absence of hypoglycemic medications, fasting blood glucose < 7.0 mmol/L and HbA1c < 6.5%. Data were analyzed using multivariable logistic regression analysis to identify predictive factors of diabetes remission. Results: We included 207 patients in this analysis; 84 (40.6%) had LSG and 123 (59.4%) had LRYGB. Half of the patients (49.8%) achieved diabetes remission at 1 year. Multivariable logistic analysis showed that LRYGB had higher odds of diabetes remission than LSG (odds ratio [OR] 6.58, 95% confidence interval [CI] 2.79­15.50, p < 0.001). Shorter duration of diabetes (OR 0.91, 95% CI 0.83­0.99, p = 0.032) and the absence of long-acting insulin (OR 0.0011, 95% CI < 0.000­0.236, p = 0.013) predicted remission. Conclusion: Type of bariatric procedure (LRYGB v. LSG), shorter duration of diabetes and the absence of long-acting insulin were independent predictors of diabetes remission after bariatric surgery.


Contexte: Il a été démontré que la chirurgie bariatrique provoque une rémission du diabète de type 2 chez les patients gravement obèses. Après la dérivation gastrique Roux-en-Y (DGRY) par laparoscopie, la rémission du diabète se produit tôt et indépendamment de la perte de poids. Des recherches antérieures ont identifié des facteurs préopératoires de rémission, notamment la durée du diabète et l'HbA1c. Comprendre les facteurs prédictifs de la rémission du diabète peut aider à sélectionner les patients qui bénéficieront le plus de la chirurgie bariatrique. Méthodes: Nous avons examiné rétrospectivement les dossiers de tous les patients atteints de diabète de type 2 qui ont subi par laparoscopie une gastrectomie en manchon (GM) ou une DGRY entre janvier 2008 et juillet 2014. Le principal résultat a été la rémission du diabète, définie comme l'absence de médicaments hypoglycémiques, la glycémie à jeun < 7,0 mmol/L et l'HbA1c < 6,5 %. Les données ont été soumises à une analyse de régression logistique multiple pour déterminer les facteurs prédictifs de la rémission du diabète. Résultats: Nous avons inclus 207 patients dans cette analyse; 84 (40,6 %) ont subi une GM et 123 (59,4 %), une DGRY. La moitié des patients (49,8 %) ont obtenu une rémission du diabète à 1 an. L'analyse logistique multiple a montré que la DGRY s'accompagnait de probabilités plus élevées de rémission du diabète que la GM (rapport de cotes [RC] 6,58; intervalle de confiance [IC] de 95 %, 2,79­15,50, p < 0,001). La durée plus courte du diabète (RC 0,91; IC de 95 %, 0,83­0,99, p = 0,032) et absence d'insuline à action prolongée (RC 0,0011; IC de 95 % < 0,000­0,236, p = 0,013) étaient prédicteurs de rémission. Conclusion: Le type d'intervention bariatrique (DGRY c. MG), la durée plus courte du diabète et l'absence d'insuline à action prolongée étaient des prédicteurs indépendants de la rémission du diabète après une chirurgie bariatrique.


Assuntos
Cirurgia Bariátrica/métodos , Diabetes Mellitus Tipo 2/terapia , Obesidade Mórbida/cirurgia , Indução de Remissão/métodos , Adulto , Glicemia/análise , Canadá , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/diagnóstico , Feminino , Hemoglobinas Glicadas/análise , Humanos , Hipoglicemiantes/uso terapêutico , Insulina de Ação Prolongada/uso terapêutico , Masculino , Pessoa de Meia-Idade , Obesidade Mórbida/sangue , Prognóstico , Estudos Retrospectivos , Fatores de Tempo , Resultado do Tratamento
10.
J Org Chem ; 84(20): 13135-13143, 2019 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-31333028

RESUMO

Palladium-catalyzed C-H bond arylation of imidazoles has been applied to pharmaceuticals such as Bifonazole, Climbazole, and Prochloraz. In the presence of phosphine-free Pd(OAc)2 catalyst, aryl bromides are efficiently coupled at the C5-position of the imidazole units, which are widely decorated. Under these conditions, only C-H bond arylation reaction occurred without affecting the integrity of chemical structure of the imidazole-based pharmaceuticals. Moreover, with Bifonazole Pd-catalyzed C-H bond diarylation at the C2- and C5-positions of imidazole unit has also been performed.

11.
Chemistry ; 25(40): 9504-9513, 2019 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-30977569

RESUMO

The potential of the heterogeneous catalyst 10 % Pd/C in the direct arylation of (poly)fluorobenzene derivatives with aryl bromides has been investigated. In general, high yields of biaryl derivatives were obtained by using tri-, tetra-, and pentafluorobenzenes, whereas mono- and difluorobenzenes exhibited poor reactivity. The regioselectivities of the arylation reactions were similar to those observed with homogeneous palladium catalysts. Both electron-withdrawing and -donating substituents, such as nitrile, nitro, acetyl, ester, trifluoromethyl, tert-butyl, methoxy, or methyl, on the aryl bromide were tolerated. Unexpectedly, tetrafluoro-substituted [1,1'-biphenyl]-4-ols were obtained from pentafluorobenzene at 150 °C due to a formal regioselective hydroxylation, whereas at lower temperatures the expected pentafluorobiphenyls were obtained. However, no C-F bond cleavage was observed with the other polyfluorobenzene derivatives. These arylation reactions were carried out with only 1 mol % Pd/C as the catalyst and KOAc as an inexpensive base. Therefore, this protocol represents a very attractive access to (poly)fluoro-substituted biphenyls in terms of cost, simplicity, and sustainable chemistry because the Pd/C catalyst can be easily removed at the end of the reaction, there is no contamination with phosphine ligand residues, and the major side-product of the reaction is KOAc⋅HBr.

12.
J Obes ; 2018: 6959786, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30002927

RESUMO

The laparoscopic Roux-en-Y gastric bypass (LRYGB) is prone to a number of complications, most notably at the gastrojejunostomy (GJ) staple line. The circular stapler technique is a common method used to create the GJ anastomosis. Although recent studies have shown a decreased rate of anastomotic strictures with shorter stapler heights, the optimal circular stapler height to use remains controversial. We therefore completed a retrospective cohort study within the Alberta Provincial Bariatric Program (APBP) to compare outcomes between the 3.5 mm and 4.8 mm stapler heights. We identified 215 patients who had a LRYGB done between the years 2015 and 2017. 143 patients had the GJ constructed with a 3.5 mm circular stapler height, with the remaining 72 patients having the GJ fashioned with a 4.8 mm stapler height. The rate of anastomotic stricturing was lower in the 3.5 mm stapler group compared to the other cohort (3.5 versus 13.9%, resp., p=0.008). Likewise, the overall rate of bleeding complications was lower in the 3.5 mm stapler group compared to the 4.8 mm group (6.3 versus 15.3%, resp., p=0.04). The rate of anastomotic stricturing and postoperative bleeding is lower with the use of a 3.5 mm circular stapler compared to a 4.8 mm circular stapler when forming the GJ.


Assuntos
Derivação Gástrica/métodos , Obesidade Mórbida/cirurgia , Grampeamento Cirúrgico/métodos , Adulto , Canadá , Constrição Patológica/prevenção & controle , Feminino , Humanos , Laparoscopia , Masculino , Pessoa de Meia-Idade , Hemorragia Pós-Operatória/prevenção & controle , Estudos Retrospectivos
13.
Org Biomol Chem ; 16(24): 4399-4423, 2018 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-29786741

RESUMO

Palladium-catalyzed reactions using aryl halides as one of the coupling partners represent a very popular method for generating carbon-carbon bonds. However, such couplings suffer from important limitations. As most palladium catalysts are very effective for the cleavage of C-halo bonds (Halo = Cl, Br or I), in many cases, the presence of several halide functional groups on arenes is not tolerated. Since two decades, and especially during the last few years, a new class of coupling partners, benzenesulfonyl and benzenesulfinate derivatives, has emerged as a powerful alternative to aryl halides for the Pd-catalyzed C-C bond formation, as the reactions performed with these substrates generally tolerate C-halo bonds. With these substrates, after a metal-catalyzed desulfitative coupling, a variety of halo-substituted arenes such as biaryls, styrenes, phenylacetylenes, acetophenones, benzonitriles… has been synthesized with high chemoselectivities. The use of these aryl sources allowed the synthesis of molecules containing several halo-substituents including iodo-substituents in only a few steps and provides very simple access to a very wide variety of halo-substituted arenes useful to materials chemists and also to biochemists. In this review, we will summarize the scope of the use of halo-substituted benzenesulfonyls and benzenesulfinates as coupling partners in metal-catalyzed C-C bond formation.

14.
J Org Chem ; 83(7): 4015-4023, 2018 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-29537843

RESUMO

The higher reactivity of the C4-H bond as compared to the C5-H bond of 1,2,3-trifluorobenzene in palladium-catalyzed direct arylation allows the selective synthesis of 4-aryl-1,2,3-trifluorobenzenes in moderate to high yields. In most cases, phosphine-free Pd(OAc)2 catalyst and inexpensive KOAc base were employed. Then, from these 4-aryl-1,2,3-trifluorobenzenes, the palladium-catalyzed C-H bond functionalization of the C6-position allows the synthesis of the corresponding 4,6-diarylated 1,2,3-trifluorobenzenes. We also applied these reaction conditions to the regioselective direct C3-arylation of 1,2,4-trifluorobenzene.

15.
Surg Endosc ; 32(6): 2620-2631, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29484554

RESUMO

BACKGROUND: Sentinel node navigation surgery (SNNS) for gastric cancer using infrared visualization of indocyanine green (ICG) is intriguing because it may limit operative morbidity. We are the first to systematically review and perform meta-analysis on the diagnostic utility of ICG and infrared electronic endoscopy (IREE) or near infrared fluorescent imaging (NIFI) for SNNS exclusively in gastric cancer. METHODS: A search of electronic databases MEDLINE, EMBASE, SCOPUS, Web of Science, and the Cochrane Library using search terms "gastric/stomach" AND "tumor/carcinoma/cancer/neoplasm/adenocarcinoma/malignancy" AND "indocyanine green" was completed in May 2017. Articles were selected by two independent reviewers based on the following major inclusion criteria: (1) diagnostic accuracy study design; (2) indocyanine green was injected at tumor site; (3) IREE or NIFI was used for intraoperative visualization. 327 titles or abstracts were screened. The quality of included studies was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2. RESULTS: Ten full text studies were selected. 643 patients were identified with the majority of patients possessing T1 tumors (79.8%). Pooled identification rate, diagnostic odds ratio, sensitivity, and specificity were 0.99 (0.97-1.0), 380.0 (68.71-2101), 0.87 (0.80-0.93), and 1.00 (0.99-1.00), respectively. The summary receiver operator characteristic for ICG + IREE/NIFI demonstrated a test accuracy of 98.3%. Subgroup analysis found improved test performance for studies with low-risk QUADAS-2 scores, studies published after 2010 and submucosal ICG injection. IREE had improved diagnostic odds ratio, sensitivity, and identification rate compared to NIFI. Heterogeneity among studies ranged from low (I2 < 25%) to high (I2 > 75%). CONCLUSIONS: We found encouraging results regarding the accuracy, diagnostic odds ratio, and specificity of the test. The sensitivity was not optimal but may be improved by a strict protocol to augment the technique. Given the number and heterogeneity of studies, our results must be viewed with caution.


Assuntos
Adenocarcinoma/cirurgia , Corantes Fluorescentes , Verde de Indocianina , Imagem Óptica/métodos , Biópsia de Linfonodo Sentinela/métodos , Linfonodo Sentinela/diagnóstico por imagem , Neoplasias Gástricas/cirurgia , Adenocarcinoma/diagnóstico por imagem , Adenocarcinoma/patologia , Endoscopia Gastrointestinal , Gastrectomia , Humanos , Metástase Linfática , Razão de Chances , Avaliação de Resultados em Cuidados de Saúde , Sensibilidade e Especificidade , Linfonodo Sentinela/patologia , Linfonodo Sentinela/cirurgia , Espectroscopia de Luz Próxima ao Infravermelho , Neoplasias Gástricas/diagnóstico por imagem , Neoplasias Gástricas/patologia
16.
Cochrane Database Syst Rev ; 1: CD012485, 2018 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-29385235

RESUMO

BACKGROUND: Aging populations are at increased risk of postoperative complications. New methods to provide care for older people recovering from surgery may reduce surgery-related complications. Comprehensive geriatric assessment (CGA) has been shown to improve some outcomes for medical patients, such as enabling them to continue living at home, and has been proposed to have positive impacts for surgical patients. CGA is a coordinated, multidisciplinary collaboration that assesses the medical, psychosocial and functional capabilities and limitations of an older person, with the goal of establishing a treatment plan and long-term follow-up. OBJECTIVES: To assess the effectiveness of CGA interventions compared to standard care on the postoperative outcomes of older people admitted to hospital for surgical care. SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase, PsycINFO, CINAHL and two clinical trials registers on 13 January 2017. We also searched grey literature for additional citations. SELECTION CRITERIA: Randomized trials of people undergoing surgery aged 65 years and over comparing CGA with usual surgical care and reporting any of our primary (mortality and discharge to an increased level of care) or secondary (length of stay, re-admission, total cost and postoperative complication) outcomes. We excluded studies if the participants did not receive a complete CGA, did not undergo surgery, and if the study recruited participants aged less than 65 years or from a setting other than an acute care hospital. DATA COLLECTION AND ANALYSIS: Two review authors independently screened, assessed risk of bias, extracted data and assessed certainty of evidence from identified articles. We expressed dichotomous treatment effects as risk ratio (RR) with 95% confidence intervals and continuous outcomes as mean difference (MD). MAIN RESULTS: We included eight randomised trials, seven recruited people recovering from a hip fracture (N = 1583) and one elective surgical oncology trial (N = 260), conducted in North America and Europe. For two trials CGA was done pre-operatively and postoperatively for the remaining. Six trials had adequate randomization, five had low risk of performance bias and four had low risk of detection bias. Blinding of participants was not possible. All eight trials had low attrition rates and seven reported all expected outcomes.CGA probably reduces mortality in older people with hip fracture (RR 0.85, 95% CI 0.68 to 1.05; 5 trials, 1316 participants, I² = 0%; moderate-certainty evidence). The intervention reduces discharge to an increased level of care (RR 0.71, 95% CI 0.55 to 0.92; 5 trials, 941 participants, I² = 0%; high-certainty evidence).Length of stay was highly heterogeneous, with mean difference between participants allocated to the intervention and the control groups ranging between -12.8 and 8.3 days. CGA probably leads to slightly reduced length of stay (4 trials, 841 participants, moderate-certainty evidence). The intervention probably makes little or no difference in re-admission rates (RR 1.00, 95% CI 0.76 to 1.32; 3 trials, 741 participants, I² = 37%; moderate-certainty evidence).CGA probably slightly reduces total cost (1 trial, 397 participants, moderate-certainty evidence). The intervention may make little or no difference for major postoperative complications (2 trials, 579 participants, low-certainty evidence) and delirium rates (RR 0.75, 95% CI 0.60 to 0.94, 3 trials, 705 participants, I² = 0%; low-certainty evidence). AUTHORS' CONCLUSIONS: There is evidence that CGA can improve outcomes in people with hip fracture. There are not enough studies to determine when CGA is most effective in relation to surgical intervention or if CGA is effective in surgical patients presenting with conditions other than hip fracture.


Assuntos
Avaliação Geriátrica , Fraturas do Quadril/cirurgia , Tempo de Internação , Neoplasias/cirurgia , Idoso , Delírio/epidemiologia , Procedimentos Cirúrgicos Eletivos/mortalidade , Fraturas do Quadril/mortalidade , Humanos , Neoplasias/mortalidade , Readmissão do Paciente/estatística & dados numéricos , Complicações Pós-Operatórias/epidemiologia , Ensaios Clínicos Controlados Aleatórios como Assunto , Resultado do Tratamento
17.
Obes Surg ; 28(2): 567-573, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29159552

RESUMO

Helicobacter pylori (HP) occurs in 50% of people worldwide with higher rates reported in the bariatric population. HP has been associated with adverse outcomes following bariatric surgery; however, its true impact has not yet been defined. We aimed to systematically review the effect of HP on bariatric surgery outcomes. A comprehensive literature review was conducted yielding seven studies with 255,435 patients. Meta-analysis found comparable rates of bleeding, leak, hospital length of stay, and weight loss between HP-positive and HP-negative patients. HP was, however, found to be the largest independent predictor of marginal ulceration in those undergoing RYGB, with a tenfold increase versus HP-negative patients. Overall, HP is associated with increased marginal ulceration rates, but has little impact on other bariatric surgery outcomes.


Assuntos
Cirurgia Bariátrica , Infecções por Helicobacter/cirurgia , Helicobacter pylori/fisiologia , Obesidade Mórbida/cirurgia , Cirurgia Bariátrica/efeitos adversos , Cirurgia Bariátrica/métodos , Infecções por Helicobacter/complicações , Infecções por Helicobacter/epidemiologia , Humanos , Obesidade Mórbida/complicações , Obesidade Mórbida/epidemiologia , Período Pós-Operatório , Estudos Retrospectivos , Resultado do Tratamento , Redução de Peso/fisiologia
18.
Chem Asian J ; 13(2): 143-157, 2018 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-29105311

RESUMO

Azulene, acenaphthylene and fulvene derivatives exhibit important physical properties useful in materials chemistry as well as valuable biological properties. Since about two decades ago, the metal-catalyzed functionalization of such compounds, via C-H bond activation of their 5-membered carbocyclic ring, proved to be a very convenient method for the synthesis of a wide variety of azulene, acenaphthylene and fulvene derivatives. For such reactions, there is no need to prefunctionalize the 5-membered carbocyclic rings. In this review, the progress in the synthesis of azulene, acenaphthylene and fulvene derivatives via metal-catalyzed C-H bond activation of their 5-membered carbocyclic ring are summarized.


Assuntos
Acenaftenos/síntese química , Azulenos/síntese química , Ciclopentanos/síntese química , Metais Pesados/química , Acenaftenos/química , Azulenos/química , Catálise , Ciclopentanos/química , Estrutura Molecular
19.
J Org Chem ; 82(7): 3886-3894, 2017 04 07.
Artigo em Inglês | MEDLINE | ID: mdl-28271711

RESUMO

Palladium-catalyzed direct arylation of 4-(2-bromophenyl)-2-methylthiazole proceeds with high efficiency at the thiazolyl C5 position using aryl bromides as the aryl source. This transformation provides simple access to 4-(2-bromophenyl)-2-methyl-5-arylthiazoles, which can be further converted into phenanthrothiazoles via palladium-catalyzed intramolecular direct arylation. When the direct arylation of 4-(2-bromophenyl)-2-methyl-5-arylthiazoles is conducted in the presence of an external heteroarene such as thiazoles, thiophenes, or imidazo[1,2-a]pyridines, the intermolecular arylation of such external heteroarenes proceeds faster than the intramolecular reaction, allowing the formation of 1,2-di(heteroaryl)benzene derivatives.

20.
Surg Endosc ; 31(8): 3078-3084, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-27981382

RESUMO

BACKGROUND: The LINX® magnetic sphincter augmentation system (MSA) is a surgical technique with short-term evidence demonstrating efficacy in the treatment of medically refractory or chronic gastroesophageal reflux disease (GERD). Currently, the Nissen fundoplication is the gold-standard surgical treatment for GERD. We are the first to systematically review the literature and perform a meta-analysis comparing MSA to the Nissen fundoplication. METHODS: A comprehensive search of electronic databases (e.g., MEDLINE, EMBASE, SCOPUS, Web of Science and the Cochrane Library) using search terms "Gastroesophageal reflux or heartburn" and "LINX or endoluminal or magnetic" and "fundoplication or Nissen" was completed. All randomized controlled trials, non-randomized comparison study and case series with greater than 5 patients were included. Five hundred and forty-seven titles were identified through primary search, and 197 titles or abstracts were screened after removing duplicates. Meta-analysis was performed on postoperative quality of life outcomes, procedural efficacy and patient procedural satisfaction. RESULTS: Three primary studies identified a total of 688 patients, of whom 273 and 415 underwent Nissen fundoplication and MSA, respectively. MSA was statistically superior to LNF in preserving patient's ability to belch (95.2 vs 65.9%, p < 0.00001) and ability to emesis (93.5 vs 49.5%, p < 0.0001). There was no statistically significant difference between MSA and LNF in gas/bloating (26.7 vs 53.4%, p = 0.06), postoperative dysphagia (33.9 vs 47.1%, p = 0.43) and proton pump inhibitor (PPI) elimination (81.4 vs 81.5%, p = 0.68). CONCLUSION: Magnetic sphincter augmentation appears to be an effective treatment for GERD with short-term outcomes comparable to the more technically challenging and time-consuming Nissen fundoplication. Long-term comparative outcome data past 1 year are needed in order to further understand the efficacy of magnetic sphincter augmentation.


Assuntos
Procedimentos Cirúrgicos do Sistema Digestório/métodos , Esfíncter Esofágico Inferior/cirurgia , Fundoplicatura/métodos , Refluxo Gastroesofágico/cirurgia , Imãs , Transtornos de Deglutição/epidemiologia , Eructação , Refluxo Gastroesofágico/tratamento farmacológico , Azia/tratamento farmacológico , Azia/cirurgia , Humanos , Laparoscopia/métodos , Satisfação do Paciente , Complicações Pós-Operatórias/epidemiologia , Inibidores da Bomba de Prótons/uso terapêutico , Qualidade de Vida , Resultado do Tratamento
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