1. Formation of diphosphates. A NMR study on the mechanism and stereochemistry of diphosphate formation from chiral dioxaphosphorinanes
- Author
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Anthony L. Spek, Bernard Feringa, N.K. de Vries, H. Kooijman, W.J.J. Smeets, Johan Visser, R.W J Zijlstra, R. Hulst, Synthetic Organic Chemistry, Faculty of Science and Engineering, and Molecular Inorganic Chemistry
- Subjects
Stereochemistry ,Side reaction ,P-31 NMR ,Alkaline hydrolysis (body disposal) ,Biochemistry ,P 31 nmr ,Catalysis ,CONFORMATIONS ,Colloid and Surface Chemistry ,UNPROTECTED AMINO-ACIDS ,6-MEMBERED RINGS ,Organic chemistry ,RATIONAL DESIGN ,RESOLVING AGENTS ,Enantiomeric excess ,chemistry.chemical_classification ,Chemistry ,ALKALINE-HYDROLYSIS ,Rational design ,General Chemistry ,Nuclear magnetic resonance spectroscopy ,PHOSPHORIC-ACIDS ,Amino acid ,ENANTIOMERIC EXCESS DETERMINATION ,Reagent ,SEMIEMPIRICAL METHODS - Abstract
During the use of chiral 2-oxo-1,3,2-dioxaphosphorinanesas derivatizing reagents in the enantiomeric excess determination of amines, alcohols, and unprotected amino acids, minor traces of side reaction products were observed by 1 H and 31 P NMR spectroscopy. Analysis of the reaction mixture showed that the side products are in fact diphosphates and several intermediates leading to their formation. From an analytical, mechanistic, and stereochemical point of view, the study of unexpected newreaction intermediates leading to diphosphates is of particular interest. Due to the easy structural modification of the starting materials in both enantiomerically pure and racemic forms as well as easy access to oxygen-labeled materials for complete structural elucidation of both intermediates and diphosphates, we accomplished a complete structural analysis. Also a mechanistic proposal for their formation proved possible using 1D and 2D 1 H and 31 P NMR techniques as well as the X-ray data of both starting material and two of the products.
- Published
- 2000