Electrocatalytic synthesis of heterocycles from biomass-derived furfuryl alcohols

Xuan Liu,Guanqun Han,De-En Jiang,Zhi Cao,Yujie Sun,Xingwu Liu,Bo Li

doi:10.1038/s41467-021-22157-5

Abstract

It is very attractive yet underexplored to synthesize heterocyclic moieties pertaining to biologically active molecules from biomass-based starting compounds. Herein, we report an electrocatalytic Achmatowicz reaction for the synthesis of hydropyranones from furfuryl alcohols, which can be readily produced from biomass-derived and industrially available furfural. Taking advantage of photo-induced polymerization of a bipyridyl ligand, we demonstrate the facile preparation of a heterogenized nickel electrocatalyst, which effectively drives the Achmatowicz reaction electrochemically. A suite of characterization techniques and density functional theory computations were performed to aid the understanding of the reaction mechanism. It is rationalized that the unsaturated coordination sphere of nickel sites in our electrocatalyst plays an important role at low applied potential, not only allowing the intimate interaction between the nickel center and furfuryl alcohol but also enabling the transfer of hydroxide from nickel to the bound furfuryl alcohol.

Highlights

It is very attractive yet underexplored to synthesize heterocyclic moieties pertaining to biologically active molecules from biomass-based starting compounds
Even though valuable products, such as polymer precursors (e.g., 2,5-furandicarboxylic acid3, 2,5-bisfuran[4], biofuels and additives (e.g., 2-methylfuran, 2,5-dimethyl furan)[5,6], and green solvents (e.g., γ-valerolactone)[7], have been obtained from biomass-derived furanics, the economic competitiveness of these bio-products against their fossil-derived counterparts is less well established if large-scale employment has yet been realized[8]
It emerges as an exciting direction to synthesize heterocyclic molecules from biomass-derived intermediate compounds, because heterocyclic motifs play pivotal roles in constructing biologically active products while biomass consists of many heterocyclic structural units[9,10]

Summary

Introduction

It is very attractive yet underexplored to synthesize heterocyclic moieties pertaining to biologically active molecules from biomass-based starting compounds. It is necessary to mention that carbon paper and DVBP required more positive potential to oxidize furfuryl alcohol and the obtained anodic currents were much less pronounced relative to the case on Ni-DVBP (Supplementary Fig. 5).

Results

Conclusion