153363-11-2Relevant academic research and scientific papers
Chemoenzymatic asymmetric synthesis of optically active pentane-1,5-diamine fragments by means of lipase-catalyzed desymmetrization transformations
Rios-Lombardia, Nicolas,Busto, Eduardo,Gotor-Fernandez, Vicente,Gotor, Vicente
scheme or table, p. 5709 - 5718 (2011/09/16)
A novel family of prochiral pentane-1,5-diamines has been efficiently synthesized, possessing stabilities significantly higher than those of corresponding propane-1,3-diamine analogues. Diamines have been later desymmetrized using Pseudomonas cepacia lipase as an efficient biocatalyst for the mono- but also stereoselective protection of one of their amino groups. Reaction parameters such as type and loading of enzyme, temperature, solvent, and acyl donor have been exhaustively analyzed, searching for optimal conditions for the production of interesting optically active nitrogenated compounds. Thus, acylation and alkoxycarbonylation processes have been compared in terms of conversion and enantiomeric excess values. The best results were found in the reaction of prochiral diamines with ethyl methoxyacetate as acyl donor and 1,4-dioxane as solvent, yielding (S)-monoamides in 33 - 59% isolated yield and 54 - 99% ee, depending on the aromatic pattern substitution.
Complementary lipase-mediated desymmetrization processes of 3-Aryl-1,5-disubstituted fragments. enantiopure synthetic valuable carboxylic acid derivatives
Rios-Lombardia, Nicolas,Gotor-Fernandez, Vicente,Gotor, Vicente
supporting information; experimental part, p. 811 - 819 (2011/04/23)
Desymmetrizaton enzymatic processes have been extensively studied searching for optimal methods of producing enantioenriched monoacetates from prochiral diols and diesters. AK lipase has been found as an excellent biocatalyst for the desymmetriaztion of a series of previously synthesized 3-arylpentane-1,5-diols derivatives. The access to (S)- or (R)-monoacetates in high optical purity (86-99% ee) has been possible by using acetylation or hydrolysis reactions, respectively, where the reaction parameters have been optimized in terms of source and amount of biocatalyst, temperature, solvent, and reaction time. The synthetic potential of enantiopure monoesters has been demonstrated by using these interesting chiral building blocks for the preparation of novel enantiopure carboxylic acid derivatives.
