Selective ring-opening of nonactivated amino aziridines by thiols and unusual nucleophilic substitution of a dibenzylamino group.
[Reaction: see text]. The reaction of chiral 2-(1-aminoalkyl)aziridines 1 with different thiols, in the presence of BF3*Et2O, is reported. The obtained products were dependent on the structure of the starting amino aziridines 1. Thus, enantiopure (2S,3S)-2-(alkylthio)alkane-1,3-diamines 2 were obtained from aziridines with C-2 substituents with lower steric congestion and partially racemized (2S,3S)-2,3-bis(alkylthio)alkan-1-amines 3 (ee = 56-66%) from aziridines with larger C-2 subtituents. In both cases, the opening of the nonactivated aziridine ring at C-2 took place with retention of configuration and proceeded with regio- and stereoselectivity at C-2. In the synthesis of 3, 2 equiv of thiol reacts with 1 and the opening of aziridine ring at C-2 was followed by an unusual displacement of the dibenzylamino group by a second equivalent of thiol. The regiochemistry and relative configuration of compounds 3 was established by single-crystal X-ray analysis. A mechanism is proposed to explain the results obtained.
Concellón
José M
JM
Departamento de Química Orgánica e Inorgánica, Facultad de Química, Universidad de Oviedo, Julián Clavería 8, 33071 Oviedo, Spain. jmcg@fq.uniovi.es
Bernad
Pablo L
PL
Suárez
José Ramón
JR
García-Granda
Santiago
S
Díaz
M Rosario
MR
D000588:Amines / Q000737:chemistry*; D001388:Aziridines / Q000737:chemistry*; D018360:Crystallography, X-Ray; D008958:Models, Molecular; D008968:Molecular Conformation; D013237:Stereoisomerism; D013438:Sulfhydryl Compounds / Q000737:chemistry*
D000588:Amines; D001388:Aziridines; D013438:Sulfhydryl Compounds