RESUMO
Atropisomeric heterobiaryls play a vital role in natural products, chiral ligands, organocatalysts, and other research fields, which have aroused great interest from chemists in recent years. Until now, a growing number of optically active heterobiaryls based on indole, quinoline, isoquinoline, pyridine, pyrrole, azole, and benzofuran skeletons have been successfully synthesized through metal or organic catalytic cross-coupling, functionalization of prochiral or racemic heterobiaryls, and ring formation. Among different strategies for the atroposelective synthesis of heterobiaryls, the strategy of ring formation has become a vital tool toward this goal. In this review, we summarize the enantioselective synthesis of axially chiral heterobiaryls through ring formation approaches, such as cycloaddition, cyclization, and chirality conversion. Meanwhile, the reaction mechanism and the corresponding applications of the chiral heterobiaryls are also discussed.
RESUMO
An effective Sc-catalyzed transfer hydrogenation and cyclization tandem reaction has been achieved. This process showed excellent functional group compatibility and good yields. A variety of benzoxazines were produced with primary or secondary alcohols as a hydrogen source. Furthermore, the utility of this newly developed protocol is demonstrated through scaled-up experiment, late-stage modification, and preliminary exploration of enantioselective synthesis.
Assuntos
Álcoois , Acetofenonas , Benzaldeídos , Catálise , Ciclização , Hidrogenação , Mesilatos , Estrutura Molecular , EscândioRESUMO
An efficient dehydrogenative inverse electron demand Diels-Alder reaction of isopropyl and prenyl benzene derivatives with electron-deficient dienes followed by decarboxylation has been reported for the first time. The much broader substrate scope of dienophiles and electron-deficient dienes led to biologically valuable pyranones in good to excellent yields.
Assuntos
Elétrons , Reação de CicloadiçãoRESUMO
OBJECTIVES: Venous thromboembolism is a potentially fatal complication of superficial endovenous treatment. Proper risk assessment and thromboprophylaxis could mitigate this hazard; however, there are currently no evidence-based or consensus guidelines. This study surveyed UK and Republic of Ireland vascular consultants to determine areas of consensus. METHODS: A 32-item survey was sent to vascular consultants via the Vascular and Endovascular Research Network (phase 1). These results generated 10 consensus statements which were redistributed (phase 2). 'Good' and 'very good' consensus were defined as endorsement/rejection of statements by >67% and >85% of respondents, respectively. RESULTS: Forty-two consultants completed phase 1. This generated seven statements regarding risk factors mandating peri-procedural pharmacoprophylaxis and three statements regarding specific pharmacoprophylaxis regimes. Forty-seven consultants completed phase 2. Regarding venous thromboembolism risk factors mandating pharmacoprophylaxis, 'good' and 'very good' consensus was achieved for 5/7 and 2/7 statements, respectively. Regarding specific regimens, 'very good' consensus was achieved for 3/3 statements. CONCLUSIONS: The main findings from this study were that there was 'good' or 'very good' consensus that patients with any of the seven surveyed risk factors should be given pharmacoprophylaxis with low-molecular-weight heparin. High-risk patients should receive one to two weeks of pharmacoprophylaxis rather than a single dose.
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Tromboembolia Venosa , Anticoagulantes , Heparina de Baixo Peso Molecular/efeitos adversos , Humanos , Irlanda/epidemiologia , Fatores de Risco , Reino Unido , Tromboembolia Venosa/epidemiologia , Tromboembolia Venosa/etiologia , Tromboembolia Venosa/prevenção & controleRESUMO
OBJECTIVE: To compare mean postoperative pain post-Lichenstein open hernioplasty with and without ilioinguinal neurectomy at six months. STUDY DESIGN: Randomised controlled trail. PLACE AND DURATION OF STUDY: Surgical Unit-I, Benazir Bhutto Hospital, Rawalpindi, from August 2014 to February 2015. METHODOLOGY: Adult male patients with unilateral reducible inguinal hernia, who consented to the study between the age range of 18-80 years, were included. Recurrent, irreducible or strangulated, or large inguinal-scrotal hernia and those with previous abdominal incision, impaired cognition, peripheral neuropathy, limited mobility and females were excluded. Patients were equally randomised to nerve-preservation and excision groups. Mann-Whitney U-test was applied to find out difference in inguinodynia at 1 and 6 months. RESULTS: There was significant difference in pain at 1 month in the nerve-preservation group (Md=6.00, IQR=4, n=90) and nerve excision group (Md=3.50, IQR=4, n=90), U=2308.00, z=-5.017, p<.001 and at 6 months in the nerve preservation group (Md=2.00, IQR=1, n=90) and nerve-excision group (Md=0.00, IQR=1, n=90), U=3001.00, z=-3.470, p=0.001. CONCLUSION: Prophylactic ilioinguinal neurectomy significantly reduces groin pain at 6 month as compared to nerve preservation group following Lichenstein hernioplasty.
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Denervação , Virilha/inervação , Hérnia Inguinal/cirurgia , Herniorrafia/métodos , Canal Inguinal/inervação , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Herniorrafia/efeitos adversos , Humanos , Canal Inguinal/cirurgia , Masculino , Pessoa de Meia-Idade , Neuralgia , Medição da Dor , Dor Pós-Operatória/epidemiologia , Dor Pós-Operatória/prevenção & controle , Período Pós-Operatório , Telas Cirúrgicas , Resultado do Tratamento , Adulto JovemRESUMO
Fewer than 40 cases of primary pleural synovial sarcoma have been reported so far with only 3 cases of cystic synovial sarcoma including cases originating from sites other than the pleura. Here, we present an exceedingly rare case of cystic synovial sarcoma originating from the mediastinal side of the visceral pleura in a 25-year man presenting with hemoptysis. On contrast-enhanced computed tomography (CT), cystic synovial sarcoma and cystic thymoma were difficult to be distinguished due to mediastinal location. Histopathological examination showed spindled morphology of tumor cells with hypercellularity and nuclear atypia. As these features are associated with both monophasic fibrous synovial sarcoma and type Athymoma, immunohistochemistry was performed. Adiagnosis of synovial sarcoma was confirmed by detection of CD99 and EMAand negativity of other markers. Fluorescence in situhybridization (FISH) was not done. Surgical excision was done and followed by oncology referral.
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Tosse/etiologia , Hemoptise/etiologia , Neoplasias Pleurais/cirurgia , Sarcoma Sinovial/cirurgia , Adulto , Humanos , Imuno-Histoquímica , Masculino , Neoplasias do Mediastino/patologia , Mediastino/patologia , Neoplasias Pleurais/patologia , Sarcoma Sinovial/patologia , Tomografia Computadorizada por Raios X , Resultado do TratamentoRESUMO
OBJECTIVE: To determine the success rate of over-under technique of myringoplasty regarding rate of graft take, complications and hearing improvement. DESIGN: Quasi-experimental study. PLACE AND DURATION OF STUDY: Department of Otorhinolaryngology and Head and Neck Surgery, Fauji Foundation Hospital, Rawalpindi from March 2003 to January 2005. PATIENTS AND METHODS: A total of 68 patients having dry central tympanic membrane perforations of various sizes secondary to chronic tubotympanic suppurative otitis media were included in the study. Over-under technique of myringoplasty was used to repair the tympanic membrane perforation. Outcome measures were graft success i.e., full or partial take, no perforation, atelactasis or lateralization within 6 months of operation and improvement in hearing. RESULTS: Sixtysix patients (97%) out of 68 had full graft take at six months of follow-up. Only one (1.5%) met with graft failure and another one (1.5%) had partial graft take. Delayed perforation was noted in two patients (3%), both of these were 10 months after surgery. Atelactasis was seen in only one patient (1.5%) eight months after operation. Lateralization did not occur in any patient. Hearing improvement was noticed in 67 (98.5%) patients. Average air bone gap decreased by 12.65 dB. CONCLUSION: Over-under myringoplasty is an effective technique of repairing the tympanic membrane perforation due to high rate of graft take, few complications and marked hearing improvement.