Nanospheric heterogeneous acid-enabled direct upgrading of biomass feedstocks to novel benzimidazoles with potent antibacterial activities

• Published in: Industrial crops and products Vol. 150; p. 112406
• Main Authors: Li, Yan, Zhou, Xiang, Wu, Hongguo, Yu, Zhaozhuo, Li, Hu, Yang, Song
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.08.2020
• Subjects: Antibacterial activity; Benzimidazoles; Biomass conversion; Green solvent; Sustainable catalysis; Antibacterial activity; Benzimidazoles; Green solvent; Biomass conversion; Sustainable catalysis
• ISSN: 0926-6690; 1872-633X
• DOI: 10.1016/j.indcrop.2020.112406

[Display omitted] •1,2-Substituted benzimidazoles in high yields (92 %) are obtained from bio-feedstocks.•The one-step cascade conversion process is enabled by a recyclable nanospheric acid.•Green and inexpensive water with superior promotional effect is used as solvent.•This protocol is applicable to producing various benzimidazoles without any additive.•Synthesized benzimidazoles exhibit good antibacterial activities in vitro and in vivo. Lignocellulosic biomass is a promising candidate for sustainable production of transportation fuels and value-added chemicals, due to its abundant and low-cost features. Benzimidazoles are prevalent in medicinal chemistry, with remarkable pharmacological and biological activities. In the present study, a facile and benign protocol of high efficiency was developed for one-step production of various benzimidazoles from bio-based aldehydes and hemicellulosic feedstocks in the presence of a heterogeneous pyridine-phosphotungstate (PY-PW) catalyst simply prepared by a room-temperature assembly method. Using water as a solvent without any oxidant, the PY-PW nanospheric catalyst is applicable to a wide range of o-phenylenediamines and bio-based aldehydes for selective synthesis of 1,2-substituted benzimidazoles in good yields (up to 92 %) at 100 °C for 1 h in a single pot via an unconventional conversion route, and could be recycled for at least 5 times with almost no decline in reactivity. Moreover, some of the sustainably synthesized benzimidazoles were examined to possess good antibacterial activities in vitro and in vivo, and can be considered as potential antibacterial agents.