Introduction
Nickel boride (Ni2B), first reported in the pioneering
work of Schlezinger and Brown
[¹]
and
traditionally used as a catalyst for hydrogenation,
[²]
has more recently found
a niche as a reducing agent in its own right.
[³]
Its
ease of preparation, handling, and versatility as a reducing agent
promise nickel boride its deserved attention from academic and industrial
sectors. Nickel boride has been employed for a wide range of transformations
including reductive dehalogenation of organic halides
[4]
, reductive amination of carbonyl
compounds,
[5]
desulfurization of a
variety of thioxo compounds,
[6]
deoxygenation
of sulfoxides and selenoxides,
[7]
and
reducing of nitrogen functionalities.
[8]
Of
late, the reagent is being explored in the form of a nickel boride silica
nanocomposite catalyst for hydrogen production from NaBH4 hydrolysis.
[9]
Preparation and Properties
The reagent can be generated by using nickel(II) salts in conjunction
with sodium borohydride in protic conditions to deposit finely divided
black precipitates of nickel boride.
[¹0]
Scheme 1
