Chiral Thiazolidine based Organocatalysts: Synthesis and Application in Asymmetric Aldol Reactions

• Autor(a) principal: Félix, Ana Rita G.
• Data de Publicação: 2020
• Outros Autores: Simões, Pedro R. D., Sousa, Francisco J. P. M., Serra, Maria Elisa Silva, Murtinho, Dina
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10316/91152; https://doi.org/10.2174/2210681209666190807155816
• topic: Thiazolidines; Organocatalyst; Aldol reaction; Enantioselective; Asymmetric synthesis; Additives

Several novel chiral organocatalysts derived from thiazolidines containing amide and thioureia functionalities were synthesized in good yields. These organocatalysts were tested in the asymmetric aldol reaction of acetone with p-nitrobenzaldehyde. Reaction parameters such as reaction time, catalyst loading and solvent were optimized. Products with conversions up to 84% and enantiomeric ratios (er) up to 84.5:15.5 (R:S) were obtained. The effect of several chiral and non-chiral additives on the reactivity and selectivity of the reaction was also evaluated. The reaction was extended to other aromatic aldehydes with the best organocatalyst and when p-bromobenzaldehyde was used, an er of 94.5:5.5 (R:S) was obtained.