Synthesis and exchange reactions of Ni-dimine-COD, acetylene and olefin complexes

Abstract

The complexes MesDADNi(COD) (1), DippDADNi(COD) (2), DippDABNiCOD (3) and DippBIANNi(COD) (5) were readily prepared from Ni(COD)₂. The analogous reaction of the ligand MesBIAN afforded (MesBIAN)₂Ni (4). The related Ni alkyne complexes DADNi(PhCCPh) (6), DippDABNi(PhCCPh) (7) and DippBIANNi(PhCCPh) (8) are readily prepared by addition of alkyne to solutions of the COD species. The analogous reactions employing tBuDAD ligand with either Ni(COD)₂ alone or Ni(COD)₂ and PhCCPh led only to the known bis-ligand Ni complex, although tBuDADNi(MeCO₂CCCO₂Me) (9) is readily prepared. In a similar fashion, the species DippDADNi(MeCO₂CCCO₂Me) (10), DippDABNi(Me₃SiCCSiMe₃) (11), DippDABNi(MeCO₂CCCO₂Me) (12) and DippBIANNi(MeCO₂CCCO₂Me) (13) were prepared. Reactions with olefins afforded DippDABNi(MeCO₂CHCHCO₂Me) (14), DippDABNi(MeCO₂CHCHPh) (15). Employing isolated (3) or (15) in exchange reactions afforded (7), (11) (14) and (15). Similarly (6) served as a precursor to (10) while (11) reacts with PhCCPh to give (7). The solid state structures of (1), (3)–(7), (9), (11) and (15) are reported.