Towards sustainability in organic transformations catalysed by 1,3-Bis (Carboxymethyl) midazole-based systems

Resumo

This doctoral thesis describes the syntheses and applications as catalysts of several systems based on the zwitterion 1,3-bis(carboxymethyl)imidazole. In Chapter 1, the synthesis of 1,3-bis(carboxymethyl)imidazole, as well as three derived imidazolium salts (chloride, bromide and iodide) and five metal-organic frameworks containing this compound as ligand (copper, calcium/chloride, calcium/bromide, barium/chloride and barium/bromide) are described. All the followed procedures require readily available materials, have a simple setup and are efficient and reproducible. In Chapter 2, the synthesis of amides starting from carboxylic acids and formamides is described by using the metal-organic framework containing copper, through an oxidative coupling. Several acids and formamides have been combined to afford a variety of amides. The methodology has been applied to the synthesis of two attractive compounds in preparative scale. In Chapter 3, the synthesis of quinolines via Friedländer reaction has been achieved using all the prepared metal-organic frameworks. These systems have proved to be complementary, that is, the formation of quinolines from each substrate depends on the system used, but this allows to have access to a variety of substituted quinolines, starting from 2-aminobenzaldehydes or 2-aminoaryl ketones. In Chapter 4, the synthesis of quinolines via Friedländer reaction has been performed by using only 1,3-bis(carboxymethyl)imidazolium chloride as promoter. A great variety of quinolines has been achieved, starting from 2-aminobenzaldehydes or 2-aminoaryl ketones, and two of them have been prepared in multigram scale. In Chapter 5, the synthesis of N-allylanilines, 2-allylanilines and 4-allylanilines from the allylic substitution of alcohols with anilines is described, the regioselectivity being provided by the different counterions of 1,3-bis(carboxymethyl)imidazolium salts: chloride, bromide and iodide. Two allylanilines have been obtained in multigram scale, proving the effectiveness of the catalysts. All the catalytic systems prepared in the present thesis have been reused for several cycles, and the processes have been performed in the absence of any solvent.