Organozinc Catalyst on a Phenalenyl Scaffold for Intramolecular Hydroamination of Aminoalkenes

The
syntheses and characterization of two organozinc compounds were accomplished
by reacting phenalenyl (PLY)-based ligands with ZnMe2.
Reactions of [HN­(Cy),O-PLY] and [HN­(Cy),N­(Cy)-PLY] ligands with ZnMe2 led to the formation of the dimeric orange-colored organozinc
compound [N­(Cy),O-PLY-ZnMe]2 (1) and red-colored
monomeric organozinc compound [N­(Cy),N­(Cy)-PLY-ZnMe] (2) under evolution of methane. Both 1 and 2 were characterized by NMR spectroscopy, elemental analysis, and
single-crystal X-ray diffraction study. The organozinc compound 2 was tested as a catalyst for intramolecular hydroamination
of both unactivated primary and secondary aminoalkenes in the presence
of an externally added activator, which generated the zinc-based cation in situ. The catalytic result obtained from the present
catalyst 2 was compared with the catalysts having similar
structure from previous studies. The DFT calculation indicates that
the stability of the in situ generated cation plays
a significant role in the catalytic activity in the hydroamination
reaction.