4,4'-Bipyridyl-Catalyzed Reduction of Nitroarenes by Bis(neopentylglycolato)diboron

Org Lett. 2019 Dec 20;21(24):9812-9817. doi: 10.1021/acs.orglett.9b03419. Epub 2019 Oct 30.

Abstract

4,4'-Bipyridyl worked as an organocatalyst for the reduction of nitroarenes by bis(neopentylglycolato)diboron (B2nep2), followed by hydrolysis to give the corresponding anilines. This reduction proceeded under aerobic conditions without any prepurification of substrates and reagents. We found broad functional group tolerance and compatibility for O- and N-protecting groups under the reaction conditions. The key in this catalytic system was the addition of B2nep2 to 4,4'-bipyridyl to form N,N'-bis[(neopentylglycolato)boryl]-4,4'-bipyridinylidene as a deoxygenating reagent of nitroarenes.