Highly Efficient and Practical Optical Resolution of 2-Amino-2′-hydroxy-1,1′-binaphthyl by Molecular Complexation with N-Benzylcinchonidium Chloride: A Direct Transformation to Binaphthyl Amino Phosphine
✍ Scribed by Kuiling Ding; Yang Wang; Hongying Yun; Jinxia Liu; Yangjie Wu; Masahiro Terada; Yasutaka Okubo; Koichi Mikami
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 128 KB
- Volume
- 5
- Category
- Article
- ISSN
- 0947-6539
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✦ Synopsis
A new type of N,P chiral ligand, binaphthyl amino phosphine 1 was synthesized through a simple and practical resolution of racemic 2-amino-2'-hydroxy-1,1'-binaphthyl by molecular complexation with 0.5 equivalents of N-benzylcinchonidium chloride in the solid state. The present procedure represents the first example of the optical resolution of amino alcohol with the use of a chiral ammonium salt as a resolving reagent. The resolution mechanism is discussed in terms of molecular recognition in solid state. The chlorine anion in N-benzylcinchonidium chloride provides the bridging link between two amino alcohol molecules [()-2] and the cinchonoid cation located in between, by hydrogen bonding with the surrounding moieties.