Screening Multicomponent Reactions for X-Linked Inhibitor of Apoptosis-Baculoviral Inhibitor of Apoptosis Protein Repeats Domain Binder

Sustainable Passerini-tetrazole three component reaction (PT-3CR): selective synthesis of oxaborol-tetrazoles

A sustainable catalyst- and solvent-free Passerini-tetrazole three component reaction (PT-3CR) has been developed for the selective synthesis of benzoxaborol-tetrazoles for the first time. The synthetic potential of oxaboroles was demonstrated towards various functionalized tetrazoles, which are otherwise difficult to achieve through conventional PT-3CR from aromatic aldehydes/ketones. The reaction features high practicality, broad substrate scope and excellent yields (80-98%). Preliminary results of the asymmetric PT-3CR are also shown for the synthesis of chiral benzoxaboroles.

Still Relevant Today: The Asinger Multicomponent Reaction

The Asinger multicomponent reaction is a versatile synthetic tool which gives access to multiple drug-like scaffolds such as 3-thiazolines. The diversity and easy access of its starting materials, its operational simplicity combined with mild conditions and relatively good yields, renders the Asinger reaction, today more than ever, a cornerstone not only in heterocyclic chemistry and modern synthesis but also in medicinal chemistry. In this review, we perform a thorough analysis of the scope and limitations on the different reaction variants with their starting materials, the three-dimensional solid-state conformations of the Asinger derivatives, and we underline and classify all the major post-modifications that have been described. In addition, we report all the major applications in drug discovery projects.

Water-triggered union of multi-component reactions towards the synthesis of a 4H-chromene hybrid scaffold

An unprecedented union of multi-component reactions to construct pyrazole- and pyranopyrazole-adorned 4H-chromene from simple reactants in water at ambient temperature is reported. This innovative tactic has integrated two distinct four-component reactions (4CRs) that occur transiently to form four new heterocycles via ten covalent bonds in a single step.

A union of multi-component reactions to construct pyrazole- and pyranopyrazole-adorned 4H-chromene from simple reactants in water at RT is reported. 2 distinct four-component reactions occur transiently to form 4 new heterocycles via 10 covalent bonds in a single step.

Expeditious access of chromone analogues via a Michael addition-driven multicomponent reaction

A Michael addition-driven four-component reaction (4-CR) with four Ugi inputs was developed and utilized for the synthesis of chromone derivatives and tetrazole substituted chromones under mild reaction conditions.

Thioacids – synthons for amide bond formation and ligation reactions: assembly of peptides and peptidomimetics

The synthesis of α-amino thioacids and peptide thioacids and their applications in chemoselective amide bond formation, ligation of peptides/proteins/glycopeptides and synthesis of peptidomimetics are reviewed.

Enthalpy-Based Screening of Focused Combinatorial Libraries for the Identification of Potent and Selective Ligands

In modern drug discovery, the ability of biophysical methods, including nuclear magnetic resonance spectroscopy or surface plasmon resonance, to detect and characterize ligand-protein interactions accurately and unambiguously makes these approaches preferred versus conventional biochemical high-throughput screening of large collections of compounds. Nonetheless, ligand screening strategies that address simultaneously potency and selectivity have not yet been fully developed. In this work, we propose a novel method for screening large collections of combinatorial libraries using enthalpy measurements as a primary screening technique. We demonstrate that selecting binders that are driven by enthalpy (ΔH) results in agents that are not only potent but also more selective for a given target. This general and novel approach, we termed ΔH screening of fPOS (enthalpy screening of focused positional scanning library), combines the principles of focused combinatorial chemistry with rapid calorimetry measurements to efficiently identify potent and selective inhibitors.

Efficient synthesis of a novel series of indeno-fused pyrido[2,3-d]pyrimidines using a deep eutectic solvent system comprised of choline chloride/urea

A series of 13 aryl indeno[2′,1′:5,6]pyrido[2,3- d]pyrimidine-2,4,6-(3 H,5 H,11 H)-triones, eight of which are new, were synthesised regioselectively in high yields by a three-component reaction of 1,3-indanedione, an araldehyde and 6-aminopyrimidin-2,4(1 H,3 H)-dione in the presence of a deep eutectic solvent comprised of choline chloride/urea (1:2) as the catalyst. The reaction conditions were mild and did not require additional catalysts. Given the inexpensive, nontoxic and recyclable nature of the deep eutectic solvent, these reaction conditions are simple to carry out and environmentally friendly.

An Efficient Passerini Tetrazole Reaction (PT-3CR)

A sonication accelerated, catalyst free, simple, high yielding and efficient method for the Passerini-type three component reaction (PT-3CR) has been developed. It comprises reaction of an aldehyde/ketone, a isocyanide and a TMS-azide in methanol:water (1:1) as the solvent system. Use of sonication not only accelerated the rate of the reaction but also provided up to quantitative yields. This reaction is applicable to a broad scope of aldehyde/ketone and isocyanides.

State-of-the-art strategies for targeting protein-protein interactions by small-molecule inhibitors

Targeting protein-protein interactions (PPIs) has emerged as a viable approach in modern drug discovery. However, the identification of small molecules enabling us to effectively interrupt their interactions presents significant challenges. In the recent past, significant advances have been made in the development of new biological and chemical strategies to facilitate the discovery process of small-molecule PPI inhibitors. This review aims to highlight the state-of-the-art technologies and the achievements made recently in this field. The "hot spots" of PPIs have been proved to be critical for small molecules to bind. Three strategies including screening, designing, and synthetic approaches have been explored for discovering PPI inhibitors by targeting the "hot spots". Although the classic high throughput screening approach can be used, fragment screening, fragment-based drug design and newly improved virtual screening are demonstrated to be more effective in the discovery of PPI inhibitors. In addition to screening approaches, design strategies including anchor-based and small molecule mimetics of secondary structures involved in PPIs have become powerful tools as well. Finally, constructing new chemically spaced libraries with high diversity and complexity is becoming an important area of interest for PPI inhibitors. The successful cases from the recent five year studies are used to illustrate how these approaches are implemented to uncover and optimize small molecule PPI inhibitors and notably some of them have become promising therapeutics.

Synthesis of tetrazoles via isocyanide-based reactions

This article provides an overview of the contributions and advances in the synthesis of tetrazoles via isocyanide-based reactions.