Synthesis of amphiphilic organocatalysts derived from L-proline

Organocatalysis, as defined by MacMillan, involves the use of low-molecular-weight organic molecules as catalysts in organic reactions. In the 21st century, significant efforts have been made to develop more sustainable organocatalyzed processes, emphasizing the production of enantiomerically pure compounds while adhering to the 12 principles of Green Chemistry. Organocatalysts synthesized from L-proline have demonstrated effectiveness in catalyzing various asymmetric reactions. Additionally, the choice of reaction medium plays a crucial role; using environmentally friendly solvents, such as water or brine solutions, can facilitate the formation of stable emulsions that enhance the interaction between the organocatalyst and the reactants. This work describes the synthesis of two organocatalysts derived from L-proline through a five-step process. The resulting compounds are (S)-7-(pyrrolidin-2-yl)tridecan-7-amine and (S)-2-(7-azidotridecan-7-yl)pyrrolidine. These compounds have two key characteristics: they are pyrrolidine derivatives functionalized at the C-2 position and they possess aliphatic chains of six carbon atoms. The obtained products were characterized using ¹H-NMR, ¹³C-NMR, DEPT, COSY, HSQC, and HMBC, with the signals confirming their proposed structures. The compounds were achieved with overall yields of 37% and 5%, respectively. A significant advantage of these products is that they can be classified as amphiphilic catalysts due to the presence of both hydrophilic and hydrophobic components in their structures. This structural feature enables the catalysts to form stable emulsions, thus promoting organic reactions in aqueous media.