Synthesis of Group 4 Metal Amides with New Chiral Biaryldiamine-Based Ligands and Their Use as Catalysts for Asymmetric Hydroamination/Cyclization

A new series of titanium(IV) and zirconium(IV) amides have been prepared from the reaction between M(NMe2)4 (M = Ti, Zr) and chiral ligands, (S)-2-(pyrrol-2-ylmethyleneamino)-2′-(dimethylamino)-1,1′-binaphthyl (4H), (R)-2-(pyridin-2-ylmethylamino)-2′-(dimethylamino)-6,6′-dimethyl-1,1′-biphenyl (6H), (S)-2-(diphenylphosphinoylamino)-2′-(dimethylamino)-1,1′-binaphthyl (7H), (R)-2-(diphenylphosphinoylamino)-2′-(dimethylamino)-6,6′-dimethyl-1,1′-biphenyl (8H), (S)-2-(mesitoylamino)-2′-(dimethylamino)-1,1′-binaphthyl (9H), (R)-2-(mesitoylamino)-2′-(dimethylamino)-6,6′-dimethyl-1,1′-biphenyl (10H), and (R)-5,5′6,6′7,7′8,8′-octahydro-2-(mesitoylamino)-2′-(dimethylamino)-1,1′-binaphthyl (11H), which are derived from (S)-2-amino-2′-(dimethylamino)-1,1′-binaphthyl (1), (R)-2-amino-2′-(dimethylamino)-6,6′-dimethyl-1,1′-biphenyl (2), or (R)-5,5′6,6′7,7′8,8′-octahydro-2-amino-2′-(dimethylamino)-1,1′-binaphthyl (3). Reaction of M(NMe2)4 with 2 equiv of 4H or 6H gives, after recrystallization from an n-hexane solution, ...