Síntese de β-Calcogenoaminas quirais via abertura regiosseletiva de Aziridinas em Líquidos Iônicos.

Abstract

The present work report the synthesis of β-chalcogen amino compounds derived from L-aminoacids. The desired products were obtained in a short reaction time, with high yields using a simple and environmentally friendly methodology. The synthetic approach involved the protected N-Boc or tosyl aziridines (2ag) ring opening using diphenyl diselenide or diphenyl disulfide (1), 10 μL of HCl (1M), zinc powder in BMIM-BF4 as solvent. The methodology allowed the synthesis of a variety of chiral β-amino selenides (3a-g) and β-amino sulfides (4a-f) with yields ranging from 65 to 92%. To afford an environmentally friendly status to the present methodology, a study concerning the ionic liquids recoverability was performed. Tests to check the efficiency of the recycled ionic liquids were realized, employing diphenyl diselenide (1a), aziridine derived from L-phenylalanine (2b), in BMIM-BF4, using HCl (1M) and zinc dust. In this way, after four successive runs, the respective compound was obtained with yields ranging from 80 to 92%. Due the wide applicability of ionic liquids as catalysts and as solvent in organic synthesis, mainly due the interesting chemical and physical properties, these compounds were chosen as reaction medium for this protocol. Besides the ionic liquids can be recovered and reused, which satisfies an environmentally friendly proposal.