In situ synthesis of rosin derived chiral derivatizing agents for 31P NMR assays of amine and alcohol enantiomers

Abstract

Chiral alcohols(3, 5) were synthesized in optically pure forms from easily available rosin acid in short-steps. A comprehensive protocol for the enantiomeric excess assays of mono-or di-functional-grouped chiral secondary amine or alcohol has been established with them used as chiral auxiliary for chiral phosphorus derivatizing agents(CPDAs) in 31P NMR tests. Chemical shift difference(Δδ P) values ranging from 4.5 to 0.15 between two diastereoisomers of the CPDAs and the aryl substrates were obtained. Positive Δδ R-S was observed for all the tested alcohol P(III) and P(V) derivatives, while negative Δδ R-S was observed for all the amines.