Tetrahydroquinoline is one of the most important simple nitrogen heterocycles, being widespread in nature and present in a broad variety of pharmacologically active compounds. This Review summarizes ...the progress achieved in the chemistry of tetrahydroquinolines, with emphasis on their synthesis, during the period from mid-2010 to early 2018.
Pyrrole is one of the most important one-ring heterocycles. The ready availability of suitably substituted and functionalized pyrrole derivatives is essential for the progress of many branches of ...science, including biology and materials science. Access to this key heterocycle by multicomponent routes is particularly attractive in terms of synthetic efficiency, and also from the environmental point of view. We update here our previous review on this topic by describing the progress made in this area in the period between mid-2009 and the end of 2013.
Multicomponent mechanochemical synthesis Leonardi, Marco; Villacampa, Mercedes; Menéndez, J. Carlos
Chemical science (Cambridge),
2018, Volume:
9, Issue:
8
Journal Article
Peer reviewed
Open access
Historically, the use of mechanochemical methods in synthesis has been almost negligible, but their perception by the synthetic community has changed in recent years and they are on their way to ...becoming mainstream. However, the hybridization of mechanochemical synthesis with methodologies designed to increase synthetic efficiency by allowing the generation of several bonds in a single operation has taken off only recently, but it already constitutes a very promising approach to sustainable chemistry. In this context, we provide in this Perspective a critical summary and discussion of the main known synthetic methods based on mechanochemical multicomponent reactions.
Multicomponent reactions promoted by mechanical energy are critically reviewed.
The use of cerium ammonium nitrate as a catalyst in the synthesis of organic compounds is examined. Reactions that involve the generation of carbon-carbon bonds include electrophilic aromatic ...substitutions.
In spite of advances in vaccination, control of the COVID-19 pandemic will require the use of pharmacological treatments against SARS-CoV2. Their development needs to consider the existence of two ...phases in the disease, namely the viral infection and the inflammatory stages. The main targets for antiviral therapeutic intervention are: (a) viral proteins, including the spike (S) protein characteristic of the viral cover and the viral proteases in charge of processing the polyprotein arising from viral genome translation; (b) host proteins, such as those involved in the processes related to viral entry into the host cell and the release of the viral genome inside the cell, the elongation factor eEF1A and importins. The use of antivirals targeted at host proteins is less developed but it has the potential advantage of not being affected by mutations in the genome of the virus and therefore being active against all its variants. Regarding drugs that address the hyperinflammatory phase of the disease triggered by the so-called cytokine storm, the following strategies are particularly relevant: (a) drugs targeting JAK kinases; (b) sphingosine kinase 2 inhibitors; (c) antibodies against interleukin 6 or its receptor; (d) use of the traditional anti-inflammatory corticosteroids.
Multicomponent reactions are one of the most interesting concepts in modern synthetic chemistry and, as shown in this critical review, they provide an attractive entry into pyrrole derivatives, which ...are very important heterocycles from many points of view including medicinal and pharmaceutical chemistry and materials science (97 references).
Proline is a non‐toxic and inexpensive natural amino acid that is readily available in both enantiomeric forms and was one of the very first compounds to be studied as an organocatalyst. Proline can ...engage in several modes of organocatalysis, as it can behave both as a Brønsted acid or a Brønsted base, and it can also easily generate the iminium or enamine intermediates that are typical of covalent organocatalysis. In view of the importance of diminishing the generation of residues formed by volatile organic solvents, the development of synthetically useful reactions that can be performed in aqueous environments is of increasing significance. The synergic combination of the advantages of water as a reaction medium with the efficiency associated to reactions that are able to generate several bonds in one operation is particularly relevant from the point of view of sustainable chemistry. In this review we critically summarize the use of proline and proline derivatives as catalysts of multi‐component reactions performed in aqueous media and leading to synthetically and biologically relevant heterocycles, a very important class of compounds that constitutes over 60% of drugs and agrochemicals.
A sequential multicomponent process involving the high-speed vibration milling of ketones with N-iodosuccinimide and p-toluenesulfonic acid, followed by addition of a mixture of primary amines, ...β-dicarbonyl compounds, cerium(IV) ammonium nitrate and silver nitrate afforded polysubstituted, functionalized pyrroles. This one-pot, solid-state process can be considered as the coupling of an α-iodoketone preparation with a general version of the classical Hantzsch pyrrole synthesis.
Brain amyloid depositions are the main hallmarks of Alzheimer's and other protein misfolding diseases. Since they are believed to precede clinical symptoms by several years, imaging of such fibrillar ...aggregates is particularly suitable to diagnose the onset of the disease in its early stage and monitor its progression. In this context, near infrared (NIR) imaging has been proposed as a promising and non-invasive method to visualize amyloid plaques in vivo because of its acceptable depth of penetration and minimal degree of tissue damage. In this tutorial review, we describe the main chemical and physicochemical features of probes associated with fluorescence emission in the NIR region. The review focuses on the recent progress and improvements in the development of small-molecule NIR fluorescent probes and their in vivo application in living animals. In addition, the possible therapeutic application of NIR probes to block the pathological aggregation process will be discussed, raising the fascinating possibility of their exploitation as theranostic agents.
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