One-pot redox cascade paired electrosynthesis of gamma-butyrolactone from furoic acid
Shengqin Liu, Yangxin Jin, Shuquan Huang, Qi Zhu, Shan Shao, Jason Chun‐Ho Lam
Abstract
Abstract The catalytic valorisation of biomass to afford synthetically useful small molecules is essential for sustainable biorefinery processes. Herein, we present a mild cascaded electrochemical protocol for converting furoic acid, a common biomass-derived feedstock, into a versatile platform chemical, gamma-butyrolactone. In the platinum(+)|nickel(−) electrode paired undivided cell, furoic acid is electrochemically oxidised with 84.2% selectivity to 2(5 H )-furanone, the olefin of which is then hydrogenated to yield gamma-butyrolactone with 98.5% selectivity. The final gamma-butyrolactone yield is 69.1% with 38.3% Faradaic efficiency and 80.1% carbon balance when the reaction is performed with 100 mM furoic acid at 80 °C at +2.0 V Ag/AgCl . Mechanistic investigation revealed the critical temperature and electrolyte pH conditions that maximise the production and protection of the key intermediate, furan radical, promoting its transition to 2(5 H )-furanone rather than self-polymerising. The reaction is scalable, as 2.1 g of 98.1% pure gamma-butyrolactone is isolated through a simple solvent extraction.