BINOL system determination

Several boron-containing species have been used as chiral NMR derivatizing agents for the analysis of primary amines or diols. " Most noteworthy among these is 2-for-mylphenylboronic acid 61, which is commercially available. Reaction of 61 with an amine and diol forms a borate-imine as shown in Scheme 50.1. The reaction can be run using an enantiomerically pure amine such as PEA to determine the enantiomeric purity of the diol, or using an enantiomerically pure diol such as BINOL to determine the enantiomeric purity of the amine.The system has been used to determine the enantiomeric purity of amines with remote chiral centers such as l-amino-4-5 ec-butylbenzene and the methyl ester of 2-methyl-5-aminopentanoic acid. 

Tucker has recently employed chiral ferrocene boronic acid 66 to electrochemically determine the enantiomeric excess of the chiral diol (binol), which took its inspiration from the three component systems used to determine enantiomeric excess of amines and diols by NMR developed by Bull and James. ... 

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