Intramolecular hydroamination of alkynes catalysed by late transition metals

摘要

The cyclisation of 6-aminohex-1-yne to 2-methyl-1, 2-dehydropiperidine in the presence of late transition metal catalysts was examined. The highest catalytic activity was observed for [Cu(CH_3CN)_4]PF_6, as well as with Group 12 metal salts. Slightly lower conversions were obtained with the rhodium (I) and palladium (II) complexes [Rh(COD)(DiPAMP)]BF_4 and [Pd(Triphos)][BF_4]_2. Catalysis was also observed with complexes of all group 9 to 12 metals and [Ru_3(CO)_(12)]. All catalytically active complexes contain a metal with a d~8 or d~(10) electronic configuration. This observation allows preliminary conclusions about the mechanism to be made.