1,4-Azaborines: Origin, Modern Synthesis, and Applications as Optoelectronic Materials

This short review summarizes the origins and recent progress in 1,4-azaborine research, focusing on synthetic methodologies. Academic laboratories have made significant efforts to generate boron-nitrogen-containing heteroaromatic compounds that mimic arenes. 1,2-, 1,3-, and 1,4-Azaborine motifs have provided breakthrough molecules in applications ranging from medicines to materials. Owing to recent advances in polyaromatic 1,4-azaborine synthesis and applications in industry, the research field is currently undergoing a renaissance. Photo- and electroluminescent properties driven by distinct structural variations are key components in the design of novel 1,4-azaborine structures. In this review, seminal reports on the synthesis of simple 1,4-azaborines to complex π-extended structures are briefly highlighted together along with key optoelectronic properties.1 Introduction2 Non-Fused 1,4-Azaborines3 Monobenzo-Fused 1,4-Azaborines4 Dibenzo-Fused 1,4-Azaborines and Their Derivatives5 Ladder-Type 1,4-Azaborines6 Complex 1,4-Azaborines7 Optoelectronic Properties of Key 1,4-Azaborines8 Conclusion and Outlook

Acetylcholinesterase Enzyme Inhibitor Molecules with Therapeutic Potential for Alzheimer's Disease

: Acetylcholinesterase (AchE), hydrolase enzyme, regulates the hydrolysis of acetylcholine neurotransmitter in the neurons. AchE is found majorly in the central nervous system at the site of cholinergic neurotransmission. It is involved in the pathophysiology of Alzheimer’s disease-causing dementia, cognitive impairment, behavioral and psychological symptoms. Recent findings involved the inhibition of AchE that could aid in the treatment of Alzheimer's. Many drugs of different classes being analyzed in the clinical trials and examined for their potency. Drugs that are used in the treatment of Alzheimer’s disease are donepezil, galantamine, tacrine, rivastigmine shows major adverse effects. To overcome this, researchers work on novel drugs to elicit inhibition. This review comprises the many hybrids and non-hybrid forms of heteroaromatic and non-heteroaromatic compounds that were designed and evaluated for AchE inhibition by Ellman’s method of assay. These novel compounds may assist the future perspectives in the discovery of novel moieties against Alzheimer’s disease by the inhibition of AchE.

Synthesis and Characterization of 1,10-phenanthroline-mono-N-oxides

N-oxides of N-heteroaromatic compounds find widespread applications in various fields of chemistry. Although the strictly planar aromatic structure of 1,10-phenanthroline (phen) is expected to induce unique features of the corresponding N-oxides, so far the potential of these compounds has not been explored. In fact, appropriate procedure has not been reported for synthesizing these derivatives of phen. Now, we provide a straightforward method for the synthesis of a series of mono-N-oxides of 1,10-phenanthrolines. The parent compounds were oxidized by a green oxidant, peroxomonosulfate ion in acidic aqueous solution. The products were obtained in high quality and at good to excellent yields. A systematic study reveals a clear-cut correlation between the basicity of the compounds and the electronic effects of the substituents on the aromatic ring. The UV spectra of these compounds were predicted by DFT calculations at the TD-DFT/TPSSh/ def2-TZVP level of theory.