Neurodegenerative disorders including Alzheimer's disease (AD) are drawing scientists' attention within various fields, being one of the most serious diseases mankind will have to fight against in the very near future. AD is multi-factorial and is characterized by two histopathological hallmarks: the senile plaques made of amyloid-β (Aβ) peptide fibrils which also contain high levels of transition metal ions and the neurofibrillary tangles of Tau protein. Aβ aggregation, possibly modulated by metal ions, is now considered as an important factor in AD aetiology. Hence, chemists are studying the details of molecular features at the origin of the disease with special interest in Aβ aggregation and in the design of new molecules for the early diagnosis of AD or with curative properties. In this context, the benzazole molecular scaffold, included for instance in Thioflavin-T, an Aβ fibril specific dye, or the PIB imaging agent, appears to be very attractive and exhibits multiple uses. In the present review, we have thus focused our interest on the applications of benzazole derivatives for understanding, diagnosing and curing AD. After having analysed the synthetic access to 2-arylbenzazoles, we have described a selection of recent applications of such compounds aiming to combat AD. They include the use of Thioflavin-T for the monitoring of Aβ aggregation, the investigations of new PET and SPECT imaging agents for the detection of the senile plaques, the development of bi-functional molecules, encompassing the 2-arylbenzazole moiety for Aβ binding and a chelating unit for metal ions coordination for instance.

The benzazole scaffold: a SWAT to combat Alzheimer's disease

This review gives an overview of the use of unusual diazonium and iodonium salts as electrophiles for the Suzuki–Miyaura reaction. The discussion mainly focuses, with a critical view, on catalytic systems developed with these electrophiles. The review also discusses their general properties and preparation as well as mechanistic aspects. A last and brief comparison of diazonium versus iodonium salts, by highlighting advantages and drawbacks of both, gives the reader an understandable resume.

Aryl Diazonium versus Iodonium Salts: Preparation, Applications and Mechanisms for the Suzuki–Miyaura Cross-Coupling Reaction

Acacetin, a flavone with diverse therapeutic potential in cancer, inflammation, infections and other metabolic disorders.

Silver catalyzed C–C and C–S coupling of aryl halides and thiols with boronic acids

This Minireview gives a complete overview of the Suzuki–Miyaura coupling reaction involving aryl diazonium salts catalyzed by heterogeneous palladium catalysts. For each process, the preparation and the properties of the heterogeneous catalysts as well as the catalytic system are critically discussed, providing their strengths and weaknesses.

Heterogeneous Palladium Catalysts for Suzuki–Miyaura Coupling Reactions Involving Aryl Diazonium Salts

Highly practical boronic acid surrogates for the Suzuki–Miyaura cross-coupling

In this work liquid phase one-step synthesis of acacetin from ethyl 3-(4-methoxyphenyl)-3-oxopropionate and phloroglucinol using PEG 1000 as solvent was examined. Heating of the reaction mixture was done with 915 MHz and 2.45 GHz microwaves at atmospheric pressure. The demethylation of the obtained acacetin using HBr at reflux led to the formation of apigenin. In view of a possible scale-up, the reaction conditions under 915 MHz microwaves were optimized to obtain high yields of acacetin. The energy required to convert phloroglucinol in acacetin was also estimated and used to calculate the total microwave power required for scaling up the process by a factor of 100. This method is an easier and cleaner synthesis for large scale preparation of flavones with good yields and purity.

Scale-up of one-step synthesis of acacetin and apigenin using 915 MHz microwaves

Aryl dioxazaborocanes are useful boronic acid surrogates for the reactions with aryl- and hetaryl bromides.

Bruno Marchiori

Papers

Highly practical boronic acid surrogates for the Suzuki–Miyaura cross-coupling

Scale-up of one-step synthesis of acacetin and apigenin using 915 MHz microwaves

Highly Practical Boronic Acid Surrogates for the Suzuki—Miyaura Cross‐Coupling.