L‐o‐Carboranylalanine, a Boron Analogue of Phenylalanine

The synthesis of a new, boron‐containing analogue of phenylalanine is described. Carboranylalanine (Car) carries a 1,2‐carborane cage in place of the benzene ring of phenylalanine. It is obtained by the reaction of derivatives of propargylglycine with decaborane. Possibilities of practical application derive from the facile neutron activation of boron nuclei with mass number 10.