Enantioselective synthesis of m-carboranylalanine, a boron-rich analogue of phenylalanine

Abstract The enantiomers of the highly lipophilic α-amino acid m -carboranyl-alanine [3-(1,7-dicarba- closo -dodecaborane(12)-1-yl)-2-aminopropanoic acid], a carborane containing analogue of phenylalanine, have been synthesised via hydroxyamination of the N -acyl derivative formed from 3-( m -carboranyl)propionic acid [3-(1,7-dicarba- closo -dodeca-borane(12)-1-yl)-2-propanoic acid] and Oppolzer's camphor sultam. The enantiomeric excess of both enantiomers of the amino acid was >98%. ( S )-Configuration was assigned to the (+)-enantiomer (CH 3 OH, 589 nm).