SynOpen最新文献

Ketyl radicals display new reactivities beyond the intrinsic electrophilicity of carbonyls. Recent progress in organic electrosynthesis has fueled the generation and utilization of ketyl radicals under ‘greener’ conditions. This graphical review summarizes these electrochemical advancements into three major categories: cross-pinacol couplings, coupling of carbonyls with alkyl radical precursors, and coupling of carbonyls with unsaturated systems (alkenes, alkynes, cyanoarenes, and N-heterocycles).

An efficient microwave-assisted Selectfluor-mediated regioselective C3-formylation of 2H-indazoles bearing a variety of alkyl and aryl substituents using DMSO as the formylating agent has been developed. This methodology provides access to 3-formyl 2H-indazoles with moderate to excellent yields. These functionalized indazoles are potentially useful as templates for drug discovery. Control experimental results suggest that this formylation probably proceeds through a radical pathway.

(Methyl 4-(diphenylphosphoryl)-2,2,5,5-tetramethyl-2,5-dihydro-1H-pyrrole-3-carboxylate-1-yl)oxydanyl was obtained as a key intermediate of the reaction starting from 3,4-dibromo-2,2,5,5-tetramethyl-2,5-dihydro-1H-pyrrol-1-yloxydanyl or (methyl 2,2,5,5-tetramethyl-2,5-dihydro-1H-pyrrole-3-carboxylate-1-yl)oxidanyl. This key compound could be converted into an azido-specific Staudinger ligation-inducing spin label, amino- and thiol-specific spin label, or MITO-CP-like antiproliferative agent.

Structural modifications of natural products has been a highly effective approach in the search for new leads with improved biological activity, aqueous solubility, and stability. Phenylethanoid glycosides (PEGs), as natural compounds, have attracted great attention due to their promising biological activities. These activities include neuroprotection, antioxidant, immunoregulation, anti-inflammatory, and analgesic effects, as well as antitumor, antiviral, and hepatoprotective abilities. Three potent PEGs, acteoside, echinacoside, and salidroside, are gaining renewed interest in this class of compounds. However, being O-glycosides, PEGs have low bioavailability due to factors such as poor intestinal permeability and low hydrolytic stability. The promising pharmacological properties and the limitations have inspired us to synthesize C-analogues that are expected to be hydrolytically stable.

A methodology for the oxidation of alcohols to aldehydes and ketones is presented. The approach employs catalytic quantities of a nitroxide and nitric acid, with no additives or metal catalysts being required. It proves effective for a range of aromatic, heteroaromatic, and aliphatic alcohol substrates, the desired products being formed in good to excellent yield. In the case of primary alcohols, the oxidation can be stopped at the aldehyde without concomitant formation of the corresponding carboxylic acid.

Three novel isomeric supramolecular allobetuline-appended 1,2,3-triazole-based potential gelators and two model compounds with cyclohexanol or undecanol fragments in the structure instead of the triterpenoid platform were synthesized. Their ability to form gels in different solvents was studied experimentally and computationally by molecular dynamics simulations and quantum chemical calculations. We found that the gelling ability of such compounds is driven by the binding energy of intermolecular tail substituent interactions. The less significant factor is the molecule unfolding in a solvent, providing that the gelling substance is actually soluble. Preferred unfolded conformations were identified by classical molecular dynamics simulation and suggested the most prospective 1,2,3-triazole-based potential gelators.

In the past few decades, zinc has attracted great attention from the scientific community due to its supreme importance in living organisms. Zinc is a trace element that is vitally important to all living organisms and it plays an important role in the immune system, wound healing, growth, and division. Therefore, the development and advancement of simple, efficient, selective, and inexpensive chemosensors for the determination of Zn²⁺ is a paramount prerequisite. Chemosensors have unique properties that are used for the specific and selective determination of several metal ions. This review summarizes the Schiff base chemosensors designed and synthesized by several research groups from the year 2018. The interaction of these probes with zinc metal ions has also been discussed briefly in this review. Furthermore, the comparison of detection limits of these probes demonstrated that the Schiff base probe possessing two benzothiazole moieties exhibits the lowest detection limit (0.00028 μM), indicating it to be the lead compound in the determination of Zn²⁺ ions in the near future.