Is the zeolite-catalyzed amination of styrenes possible?

The direct amination of olefins is an elegant and environmentally benign pr ocedure to form amines as could be nicely demonstrated in the BASF tert-but ylamine process. Therefore, it was of great interest to synthesize the valu able intermediate 1-phenyl-ethylamine according to that method. The convers ion of styrene to the desired amine is feasible, but strongly limited by th e thermodynamic equilibrium. Furthermore, the strong tendency of styrene to polymerize hinders a smooth reaction to 1-phenyl-ethylamine. The reaction was carried out in the presence of weakly acidic zeolites such as H-B-MFI a nd H-B-BEA under various reaction conditions. Due to the results, the direc t amination of styrene seems to be not possible with high yields whereas th e nucleophilic substitution of the 1-phenylethanol with ammonia yields the desired amine. Such investigations have been also transferred to other styr ene derivatives. (C) 2000 Elsevier Science B.V. All rights reserved.