Enantiopure O-ethyl (2-naphthyl)phosphonothioic acid 1 was designed on the model of O-ethyl phenylphosphonothioic acid, based on the fact that the chiral recognition abilities of enantiopure mandelic acid and cis-1-aminoindan-2-ol were improved upon by replacing their phenyl/phenylene groups with naphthyl/naphthylene groups, respectively. Enantiopure 1 was easily obtained by the enantioseparation of racemic 1, which was easily synthesized from commercially available 2-bromonaphthalene and diethoxyphosphonothioic chloride, with enantiopure 1-phenylethylamine. Enantiopure 1 showed an excellent chiral recognition ability for several 1-arylethylamine derivatives during the diastereomeric salt formation. The effect of the enlarged aromatic part of 1 is discussed on the basis of X-ray crystallographic analyses. © 2006 Elsevier Ltd. All rights reserved.
Kobayashi, Y., Maeda, J., & Saigo, K. (2006). Synthesis and chiral recognition ability of O-ethyl (2-naphthyl)phosphonothioic acid. Tetrahedron Asymmetry, 17(11), 1617–1621. https://doi.org/10.1016/j.tetasy.2006.06.002