Hydroamination of 6-aminohex-1-yne over zinc based homogeneous and zeolite catalysts

Abstract

Ion-exchanged zeolites are efficient heterogeneous catalysts for the intramolecular addition of an amine H–NR 2 to a CC triple bond. This was shown for the cyclisation of 6-aminohex-1-yne to 2-methyl-1,2-dehydropiperidine. For this reaction zinc(II)-exchanged zeolite BEA was one of the most active catalysts. The heterogeneous catalyst was more active than the corresponding homogeneous catalyst Zn(CF 3SO 3) 2, which is concluded to be related to co-catalysis between Lewis and Br ønsted acid sites present in the zeolite.