Azobenzenes are ubiquitous motifs very important in many areas of science. Azo compounds display crucial properties for important applications, mainly for the chemical industry. Because of their discovery, the main application of aromatic azo compounds has been their use as dyes. These compounds are excellent candidates to function as molecular switches because of their efficient cis–transisomerization in the presence of appropriate radiation. The classical methods for the synthesis of azo compounds are the azo coupling reaction (coupling of diazonium salts with activated aromatic compounds), the Mills reaction (reaction between aromatic nitroso derivatives and anilines) and the Wallach reaction (transformation of azoxybenzenes into 4-hydroxy substituted azoderivatives in acid media). More recently, other preparative methods have been reported. This critical review covers the various synthetic methods reported on azo compounds with special emphasis on the more recent ones and their mechanistic aspects (170 references).

http://www.chtf.stuba.sk/~szolcsanyi/education/files/Organicka%20chemia%20II/Prednaska%202_Aminy_Reakcie/Doplnkove%20studijne%20materialy/Azobenzenes/Synthesis%20of%20azobenzenes%20-%20the%20coloured%20pieces%20of%20molecular%20materials.pdf

Synthesis of azobenzenes: the coloured pieces of molecular materials

Bromination is one of the most important transformations in organic synthesis and can be carried out using bromine and many other bromo compounds. Use of molecular bromine in organic synthesis is well-known. However, due to the hazardous nature of bromine, enormous growth has been witnessed in the past several decades for the development of solid bromine carriers. This review outlines the use of bromine and different bromo-organic compounds in organic synthesis. The applications of bromine, a total of 107 bromo-organic compounds, 11 other brominating agents, and a few natural bromine sources were incorporated. The scope of these reagents for various organic transformations such as bromination, cohalogenation, oxidation, cyclization, ring-opening reactions, substitution, rearrangement, hydrolysis, catalysis, etc. has been described briefly to highlight important aspects of the bromo-organic compounds in organic synthesis.

Use of Bromine and Bromo-Organic Compounds in Organic Synthesis

Interactions between 1-benzoyl-4-p-chlorophenyl thiosemicarbazide and serum albumin: investigation by fluorescence spectroscopy

Centro de Quı́mica-Fı́sica Molecular (CQFM) and Institute of Nanosciences and Nanotechnology (IN), Departamento de Engenharia Quı́mica e Biológica, Instituto Superior Técnico, 1049-001 Lisboa, Portugal, REQUIMTE, Departamento de Quı́mica, Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa, Quinta da Torre, 2829-516 Caparica, Portugal, and iMed.UL, Faculdade de Farmácia da Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal

More sustainable approaches for the synthesis of N-based heterocycles.

http://www.chtf.stuba.sk/~szolcsanyi/education/files/Organicka%20chemia%20II/Prednaska%202_Aminy_Reakcie/Doplnkove%20studijne%20materialy/Azobenzenes/Azobenzenes-synthesis%20and%20carbohydrate%20applications.pdf

Azobenzenes—synthesis and carbohydrate applications

A new and efficient solid state synthesis of diaryl thioureas

An efficient and a quick microwave-assisted synthesis of benzimidazoles and trisubstituted imidazoles was developed. Three benzimidazoles were obtained as a result of the condensation of 1,2-phenylenediamine with carboxylic acids and acetoacetic ester without catalyst. A series of trisubstituted imidazoles were synthesized by condensation of benzil, aromatic aldehyde and ammonium acetate in the presence of glacial acetic acid.

Yu-Lu Wang

Papers

A new and efficient solid state synthesis of diaryl thioureas

A Rapid and Convenient Synthesis of Derivatives of Imidazoles under Microwave Irradiation

The Preparation of Symmetrical Azobenzenes from Anilines by Phase Transfer Catalyzed Method

An efficient oxidation arylsemicarbazides to the azo ureas

A high-selectivity spectrophotometric reagent for determining platinum(IV).