Suitable Approach to Prepare N‐Substituted Niobium Complexes – Study of the Factors Controlling the Process

Abstract

The reactions of the chlorosilyl-substituted cyclopentadienyl niobium compound [Nb(η 5 -C 5 H 4 SiMe 2 Cl)Cl 4 ] (1) with 1 equiv. of 2-methoxyethylamine, 3-methoxypropylamine, and allylamine in toluene specifically afford the corresponding amine adducts [Nb(η 5 -C 5 H 4 SiMe 2 Cl){NH 2 (CH 2 ) n OMe}Cl 4 ] (n = 2, 2; 3, 3) and [Nb(η 5 -C 5 H 4 SiMe 2 Cl)(NH 2 CH 2 CH=CH 2 )Cl 4 ] (4). In contrast, a similar reaction with 1,2-phenylenediamine proceeds with the aminolysis of a Nb-Cl bond and the formation of the amido-amine compound [Nb(η 5 -C 5 H 4 SiMe 2 Cl)(NHC 6 H 4 -2-κNH 2 )Cl 3 ] (5). When such reactions are performed in the presence of 2 equiv. of an additional base, they progress through [a]