Catalytic Reductions and Tandem Reactions of Nitro Compounds Using in Situ Prepared Nickel Boride Catalyst in Nanocellulose Solution

Abstract:

With the emergence and development of nanotechnology, nanocellulose attracts more attention as cheap, renewable, and biodegradable materials. Nanocellulose has a large surface area and their functionalizable surface make them interesting as support for catalysis. In addition, nanocellulose suspensions in water are very stable and add enhanced stability to metal catalysts supported by them. The most developed approach has been to use nanocellulose as support for metal nanoparticles (NPs) and, for instance, hybrids materials made of cellulose supported silver, gold, cadmium, iron, and nickel nanoparticles¹. However, the production of nickel-based nanoparticles supported on nanocellulose has been more scarce.

The reduction of nitro groups into amines represents one of the most straightforward entries to aliphatic or aromatic amines². Here we wish to present a mild, highly efficient, and practical chemical protocol for the reduction of nitro groups into amines using nanocellulose-supported nickel boride (Ni₂B-NCF) using only water as a solvent and NaBH₄ as mild reducing agent³ (see scheme below).

The protocol is able to reduce a large number of nitro compounds at room temperature with low catalyst loading (0.25 mol% of NiCl₂) in high isolated yields. Similarly, we have developed a tandem reaction methodology to prepare a b-amino alcohol by mixing of an epoxide and nitrobenzene in water under the developed reduction condition.

References

1. Kaushik, M, Moores, A, Green Chem. 2016, 18, 622-637
2. Downing, R.S. Kunkeler, P, J. van Bekkum, H, Catal. Today 1997, 37, 121-126.
3. Prathap, K. J, Qiong W, Richard T. O, Peter D, Org. Lett., 2017, 19, 4746-4749