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The high atom-economical and eco-benign nature of hydrogenation reactions make them much more superior to conventional reduction and transfer hydrogenation. Herein, a convenient and highly selective hydrogenation reaction of azoarenes using molecular hydrogen to access diverse hydrazoarenes is reported. The present catalytic method is general and operationally simple, and it operates under exceedingly mild conditions (room temperature and 1 atm of hydrogen pressure). The reusability of catalysts used in this method is also successfully demonstrated.
RESUMEN
Visible light-mediated photocatalytic organic transformation has drawn significant attention as an alternative process for replacing thermal reactions. Although precious metal/organic dyes based homogeneous photocatalysts have been developed, their toxic and nonreusable nature makes them inappropriate for large-scale production. Therefore, we have synthesized a triazine and a keto functionalized nonmetal based covalent organic framework (TpTt) for heterogeneous photocatalysis. As the catalyst shows significant absorption of visible light, it has been applied for the photocatalytic uphill conversion of trans-stilbene to cis-stilbene in the presence of blue light-emitting diodes with broad substrate scope via an energy transfer process.
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We report here for the first time the catalytic oxidative dehydrogenation of N-heterocycles by a visible-light organo-photoredox catalyst with low catalyst loading (0.1-1â mol %). The reaction proceeds efficiently under base- and additive-free conditions with ambient air at room temperature. The utility of this benign approach is demonstrated by the synthesis of various pharmaceutically relevant N-heteroarenes such as quinoline, quinoxaline, quinazoline, acridine, and indole.
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A range of α-aryl substituted γ-ketophosphonates is synthesised by Lewis acid mediated reactions of 1,3-diketones and easily accessible, inexpensive benzylic α-hydroxyphosphonates in an operationally simple method under solvent-free conditions without exclusion of air/moisture. A regioselective C-C bond cleavage for 1,3-diketones in a tandem fashion has also been demonstrated. Synthesis of a γ-ketophosphonate with phenol functionality at the α-position (structural analogue of raspberry ketone, a natural product) has also been presented.
Asunto(s)
Cetonas/química , Cetonas/síntesis química , Ácidos de Lewis/química , Organofosfonatos/química , Organofosfonatos/síntesis química , Compuestos Férricos/química , Mesilatos/química , Estructura Molecular , EstereoisomerismoRESUMEN
Women with schizophrenia have a high risk for symptom exacerbation or relapse during pregnancy and thereafter. Relapses are more frequent when antipsychotics are discontinued. Continuation of antipsychotic during pregnancy has become common and olanzapine is commonly prescribed antipsychotic. It is very important to know the safety profile of olanzapine in Indian settings. Aim of our paper is to report two cases of olanzapine use pregnancy, discuss its safety profile, and adverse effects on mother and foetus. In both of our cases, olanzapine was continued throughout pregnancy and the patients remain clinically stable as per psychiatric symptoms. In case 1 whole antinatal and perinatal period was normal except patient has oligohydramnios and low birthweight baby and in case 2 she had oligohydramnios and large baby. Our cases add to the safely data of use of olanzapine in pregnancy, particularly in Indian settings. While conclusive elucidation still awaits more such reports from India and well-controlled studies.
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Portal hypertensive bleeding is a major complication of portal hypertension (PHT) with high morbidity and mortality. A lot of advances have been made in our understanding of screening, risk stratification, and management strategies for portal hypertensive bleeding including acute variceal bleeding leading to improved overall outcomes in patients with PHT. A number of guidelines on variceal bleeding have been published by various societies in the past few years. The Indian Society of Gastroenterology (ISG) Task Force on Upper Gastrointestinal Bleeding (UGIB) felt that it was necessary to bring out a standard practice guidance document for the use of Indian health care providers especially physicians, gastroenterologists, and hepatologists. For this purpose, an expert group meeting was convened by the ISG Task Force to deliberate on this matter and write a consensus guidance document for Indian practice. The delegates including gastroenterologists, hepatologists, radiologists, and surgeons from different parts of the country participated in the consensus development meeting at Coorg in 2018. A core group was constituted which reviewed all published literature on portal hypertensive UGIB with special reference to the Indian scenario and prepared unambiguous statements on different aspects for voting and consensus in the whole group. This consensus was produced through a modified Delphi process and reflects our current understanding and recommendations for the diagnosis and management of portal hypertensive UGIB in Indians. Intended for use by the health care providers especially gastroenterologists and hepatologists, these consensus statements provide an evidence-based approach to risk stratification, diagnosis, and management of patients with portal hypertensive bleeding.
Asunto(s)
Várices Esofágicas y Gástricas , Gastroenterología , Hipertensión Portal , Consenso , Várices Esofágicas y Gástricas/complicaciones , Várices Esofágicas y Gástricas/diagnóstico , Hemorragia Gastrointestinal/diagnóstico , Hemorragia Gastrointestinal/etiología , Hemorragia Gastrointestinal/terapia , Humanos , Hipertensión Portal/complicaciones , Hipertensión Portal/diagnóstico , Hipertensión Portal/terapiaRESUMEN
Here, the first example is reported of a new, molecularly defined SNS-cobalt(ii) catalyst for the acceptorless dehydrogenative coupling (ADC) of unprotected amino alcohols with secondary alcohols leading to pyrrole and pyridine derivatives.
RESUMEN
Children under 19 years of age constitute over 40% of India's population and information about their mental health needs is a national imperative. Children with specific learning disorders (SLDs) exhibit academic difficulties disproportionate to their intellectual capacities. Prevalence of SLD ranges from 2% to 10%. Dyslexia (developmental reading disorder) is the most common type, affecting 80% of all SLD. About 30% of learning disabled children have behavioral and emotional problems, which range from attention deficit hyperactivity disorder (most common) to depression, anxiety, suicide etc., to substance abuse (least common). Co-occurrence of such problems with SLD further adds to the academic difficulty. In such instances, diagnosis is difficult and tricky; improvement in academics demands comprehensive holistic treatment approach. SLD remains a large public health problem because of under-recognition, inadequate treatment and therefore merits greater effort to understand the co-morbidities, especially in the Indian population. As the literature is scarce regarding co-morbid conditions in learning disability in Indian scenario, the present study has tried to focus on Indian population. The educational concessions (recent most) given to such children by Central Board of Secondary Education, New Delhi are referred to. The issues to be addressed by the family physicians are: Low level of awareness among families and teachers, improper dissemination of accurate information about psychological problems, available help seeking avenues, need to develop service delivery models in rural and urban areas and focus on the integration of mental health and primary care keeping such co-morbidity in mind.
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Development of multicatalytic approach consisting of two or more mechanistically distinct catalytic steps using a single-site catalyst for rapid and straightforward access of structurally complex molecules under eco-benign conditions has significance in contemporary science. We have developed herein a rhodium-catalysed C-H activation strategy which uses an unprotected anilines and an electron-deficient alkynes to C-C bonded products as a potential intermediate in contrast to the archetypical C-N bonded products with high levels of regioselectivity. This is followed by carbonylation of C-H bond activated intermediate and subsequent annulation into quinolines has been described. This rhodium-catalysed auto-tandem reaction operates under mild, environmentally benign conditions using water as the solvent and CO surrogates as the carbonyl source with the concomitant generation of hydrogen gas. The strategy may facilitate the development of new synthetic protocols for the efficient and sustainable production of chemicals in an atom-economic way from simple, abundant starting materials.
RESUMEN
The first example of ligand-enabled C(sp(3))-alkynylation of 8-methylquinoline is reported. The reaction is catalysed by well-defined Pd(ii) complexes. The present C(sp(3))-alkynylation has a broad substrate scope as well as functional group tolerance and proceeds efficiently under mild conditions.