NbCl4 thf

Metathetical reactions between NbCl4(THF)2, NbCls, TaCls, [(Et2N)2TaCl3]2, or (R2N)3Ta(=NBu (R = Me, Et) with various amounts of lithium amidinates have been employed to synthesize the corresponding heteroleptic niobium and tantalum amidinate complexes. The products were investigated as potential precursors to metal nitrides (cf. Section VI) Carbodiimide insertion routes... 

In a similar type of process, imines have been dimerized to give 1,2-diamines, by a number of procedures, including treatment with TiCLj—In/aqueous EtOH, Zn/aqueous NaOH, Cp2VCl2/Zn/PhMe2SiCl, with Sml2, and I for silylated imines) NbCl4(thf)2. When electroreduction was used, it was even... 

Niobium(IV) chloride, NbCl4(THF)2. This reagent (1) can be obtained1 by reduction of NbCl5 with aluminum powder in CH,CN followed by solvation with THF m.p. 110° dec., yield 50%. 

In 1987, Pedersen reported that reductive coupling of A -(trimethylsilyl)imines (or a combination of nitriles and BusSnH) occurred with NbCl4(THF)2 in DME to give 1,2-diamines in 40-73% yields (Equation (67)). ... 

Nb15 iminoethyl derivatives have been obtained by insertion of Bu NC into the Nb—Cl bond of [NbCl4(THF)2] and substitution of the remaining chlorine. The products... 

Nb(CO)6] (38) has become accessible in high yield by reduction of NbCl4(THF)2 at atmospheric pressure (Scheme 7). [Nb(PF3)6] is accessible either by photolysis (see Photosynthesis) of [Nb(CO)6] under PF3 or by a reductive route similar to that of (38). The Nb NMR chemical shifts suggest weaker Nb-PFs bonds than Nb-CO ones. ... 

A four-coordinate NbOL3 molecule resulted from the reaction of NbCl4(thf)2 and LiL = LiN(SiMe3)2 via oxygen abstraction from solvent thf. The low coordination number is imposed by the steric demands of the amido ligand.249 An equivalent structure resulted from reaction of MOCl3 with a lithiated aza-2,5-disila-cyclo-pentane ligand (125).250... 

Reduction of NbCl4(thf)2 or Ta2Cli0 with alkali metal arenides in ether solvents at — 60 °C provided, after work-up, salts of the homoleptic arene complexes [M IL3] ((271) L = -naphthalene, 1 -4- 74-anthracene).663 664... 

The first tris(arene) niobium complex, [Nb(l-4-jj -anthracene)3], prepared by the Na or K anthracene reduction of NbCl4(THF)2, undergoes facile anthracene displacement in the presence of CO to afford [K(18-crown-6)(THF)2][Nb(CO)6]. Reduction of TaCls by sodium naphthalene provides [Na(THF)][Ta(jj -naphthalene)3], the first homoleptic naphthalene complex of a third row transition metal. This complex reacts with CO and anthracene to give [Ta(CO)e] and [Ta(l-4-jj -anthracene)3], respectively. The latter product reacts with cyclooctatetraene (COT) to give [Ta(COT)3]-.==i= ... 

Coupling of radicals obtained from cyanides has provided a useful route to diamines The radical is generated by addition of NbCl4(THF)2 and is probably stabilized by the complex formed. 

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