Efficient and practical synthesis of modular chiral β-organochalcogeno amines, ArYCH2CH(R)NH2, and single crystal structures of [formula omitted] and [formula omitted

Abstract

Modular chiral β-organochalcogeno amines, ArYCH2CH(R)NH2 (4a-4g) where R = Me, Bz, Ph; and ArY = PhS, BzSe and 4-MeOC6H4Te respectively have been synthesized and characterized. Compounds 4a-4g were synthesized (Method II) from chiral aminoalkyl β-methanesulfonate hydrochlorides, MsOCH2CH(R)NH3+·Cl− (2a-2c) through nucleophilic displacement of MsO− with organochalcogenolate (ArY−). In another attempt (Method I) chiral β-organotelluro amines (4a-4c) were prepared by deprotection of chiral N-boc β-organotelluro amides, 4-MeOC6H4TeCH2CH(R)NH-Boc (3a-3c), which in turn were made from chiral N-boc β-methanesulfonate amides (1a-1c) and ArTeNa. 1H, 13C{1H} NMR and FT-IR spectra of all the compounds (3a-3c and 4a–4g) were characteristic. The composition of 3a-3c was determined by elemental analysis. The [α]DT values of 3b-3c and 4a-4g were determined. The single crystal structures of (S)-2b and (R)-2c were determined by X-Ray diffraction studies. Both (S)-2b and (R)-2c were crystallized in orthorhombic system and the Flack parameter x was found −0.08(12) and 0.00(2) respectively. The crystal of (S)-2b contain two asymmetric units with gauche (A) and staggered (B) conformations. There are NH⋯Cl−, NH⋯O and CH⋯O intra and intermolecular secondary interactions in (S)-2b and (R)-2c resulting in supramolecular structures.