A mild and selective Cu(II) salts-catalyzed reduction of nitro, azo, azoxy, N-aryl hydroxylamine, nitroso, acid halide, ester, and azide compounds using hydrogen surrogacy of sodium borohydride

Abstract

The first mild, in situ, single-pot, high-yielding well-screened copper (II) salt-based catalyst system utilizing the hydrogen surrogacy of sodium borohydride for selective hydrogenation of a broad range of nitro substrates into the corresponding amine under habitancy of water or methanol like green solvents have been described. Moreover, this catalytic system can also activate various functional groups for hydride reduction within prompted time, with low catalyst-loading, without any requirement of high pressure or molecular hydrogen supply. Notably, this system explores a great potential to substitute expensive traditional hydrogenation methodologies and thus offers a greener and simple hydrogenative strategy in the field of organic synthesis.

Graphical Abstract

Keywords:

• Sodium borohydride
• copper (II) salts
• chemo- and regioselective reduction

Supplementary information

The supporting information contains experimental details, General methods, characterization data, and copies of ¹H NMR and ¹³C NMR spectra of the products.

Acknowledgments

This research was supported by the Department of Chemistry, Sardar Patel University. Authors are grateful to UGC, New Delhi for the UGC-CPEPA Phase-II program sponsored under award letter no. F. No. 1-14/2002-2016 (NS/PE) dated April 28, 2016 as well as UGC-CAS, Phase-II sponsored under award letter no. F-540/5/CASII/2018 (SAP-I) dated July 25, 2018, for assistance in general. One of the authors (Jaydeep A. Mokariya) is grateful to the CSIR, New Delhi, for a CSIR-JRF.

Disclosure statement

The authors declare no conflict of interest.