Organoniobium chemistry

They are obtained by reduction of NbCl5 under an atmosphere of CO. A wide variety of alkyl Nb compounds have been prepared.

Low coordination number complexes require the absence of any β-hydrogen to prevent rapid β-hydride elimination.

[5] Along with the related organotantalum species, niobium alkylidenes were among the first Scrock carbenes studied.

[6] Similar to other d2 transition metals, Nb(III) produce adducts with alkynes.

A prominent early synthetic application of organoniobium chemistry was the use of dimethoxyethane niobium trichloride, NbCl3(DME), as a reagent for the reductive coupling of imines with carbonyl compounds to form amino alcohols.

Structure of [Li(OEt 2 ) 3 ] + [NbMe 6 ] − .
Niobocene dichloride ( (C 5 H 5 ) 2 NbCl 2 ).
The adducts from Nb(III) and alkynes are often described as metallacyclopropenes.
NbCl 3 (DME) mediated reductive coupling. Hydrolysis step is shown with implicit water.
Nb(III) catalyzed formal [2+2+2] cycloadditions
Nb(III) catalyzed alkyne semihydrogenation