New environmentally friendly procedures for the synthesis of biologically active compounds by C-C and C-heteroatom bond formation
Author(s)
Maurone, Loredana
Date Issued
June 25, 2013
Type
Doctoral Thesis
Abstract
Over the last few years, industry focused its efforts on the development of new technologies for pollution prevention. This approach is the way of modern business. It uses less energy, requires minimal product separations, generally involves less capital investment and there is no impact on the environment. In the last years, green chemistry has been recognized as a new approach to scientifically based environmental protection. Green chemistry “is the design of chemical products and processes which reduce or eliminate the use and the generation of hazardous substances in the design, manufacture and application of chemical products”. It utilizes a set of twelve principles and in this context catalysis plays a fundamental role. In the last decades, palladium-catalyzed reactions have become an important and extremely flexible tool for practicing organic chemists. As palladium chemistry is generally tolerant of a wide range of functionalities, it is applicable to complex molecules. Thus, a large number of fine chemicals and biologically active ingredients have been prepared in fewer steps and with less wastes than classical methods. Even the design of heterocyclic synthesis has been deeply influenced and modified by the growing utilization of palladium catalysis, as testified by the wide amount of studies on the palladium-catalyzed synthesis and functionalization of heterocycles. In this context, the research activity carried out during this PhD course has been devoted to the development of environmentally friendly procedures for the synthesis of new biologically active compounds through palladium-catalyzed assisted processes. At the same time, a new kind of supported gold nanoparticles has been prepared, characterized and tested as new oxidant system. Specifically:
1) a new synthetic strategy for the synthesis of 5-aryl-dopamine and 5-alkynyl- dopamine derivatives starting from protected 4-(2-aminoethy)phenol through the sequence halogenation/palladium catalyzed cross-coupling alkynylation has been optimized. The new derivatives could be used as starting materials for pharmaceutical chemicals;
2) a novel palladium-catalyzed approach to 2-amino ketones has been developed. This procedure is based on the reaction between arylpropargyl carbonates, bearing neutral, electron-rich, and electron-poor aromatic rings, and cyclic secondary amines containing useful functional groups such as cyano, chloro and bromo substituents. This procedure is simple, uses readily available starting materials and represents an useful tool for a new approach to the synthesis of this class of compounds;
3) a new straightforward synthesis to 3-substituded indole derivatives has been developed through a cascade process involving N-arylpropargyl bromide and arylboronic acids;
4) new active gold nanoparticles stabilized by polysaccharides have been prepared and tested in the alcohols oxidation, obtaining good results in term of selectivity, yield and reaction time.
Additional information
Dottorato di ricerca in Scienze ambientali
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