16874-33-2Relevant articles and documents
Gram-scale synthesis of carboxylic acids via catalytic acceptorless dehydrogenative coupling of alcohols and hydroxides at an ultralow Ru loading
Chen, Cheng,Cheng, Hua,Verpoort, Francis,Wang, Zhi-Qin,Wu, Zhe,Yuan, Ye,Zheng, Zhong-Hui
, (2021/12/13)
Acceptorless dehydrogenative coupling (ADC) of alcohols and water/hydroxides is an emergent and graceful approach to produce carboxylic acids. Therefore, it is of high demand to develop active and practical catalysts/catalytic systems for this attractive transformation. Herein, we designed and fabricated a series of cyclometallated N-heterocyclic carbene-Ru (NHC-Ru) complexes via ligand tuning of [Ru-1], the superior complex in our previous work. Gratifyingly, gram-scale synthesis of carboxylic acids was efficiently enabled at an ultralow Ru loading (62.5 ppm) in open air. Moreover, effects of distinct ancillary NHC ligands and other parameters on this catalytic process were thoroughly studied, while further systematic studies were carried out to provide rationales for the activity trend of [Ru-1]-[Ru-7]. Finally, determination of quantitative green metrics illustrated that the present work exhibited superiority over representative literature reports. Hopefully, this study could provide valuable input for researchers who are engaging in metal-catalyzed ADC reactions.
Cascade conversion of furancarboxylic acid to butanediol diacetate over Pd/C and La(OTf)3 catalytic system
Deng, Jin,Fu, Yao,Gong, Baoxiang,Zhou, Gongyu,Zhu, Rui
, (2020/11/12)
The conversion of biomass to a high value-added product 1, 4-butanediol (BDO) and its derivatives is of great economic significance. In this work, furancarboxylic acid (FCA) was adopted as the raw material to prepare BDO. The one-pot synthesis of 1, 4-butanediol diacetate (BDA) has been successfully prepared from FCA with metal triflates and Pd/C catalysts. The effect of reaction conditions was investigated and the reaction routes was systematically studied by 1H-NMR and GC. The tandem catalytic process from FCA to BDA mainly underwent three stages. Firstly, FCA was hydrogenated to tetrahydrofurfuric acid (THFCA) by Pd/C. Afterwards, THFCA was decarbonylated to form oxonium ions with metal triflates. Then the oxonium ions was rapidly hydrogenated to form tetrahydrofuran (THF) by Pd/C. Ultimately, THF was ring-opening esterified to BDA by metal triflates. This novel synthesis method of BDO from FCA provides a promising protocol for broadening the application of common biomass substrates.
Selective Hydrogenolysis of α-C-O Bond in Biomass-Derived 2-Furancarboxylic Acid to 5-Hydroxyvaleric Acid on Supported Pt Catalysts at Near-Ambient Temperature
Sun, Qianhui,Wang, Shuai,Liu, Haichao
, p. 11413 - 11425 (2019/11/21)
Hydrogenolysis of the α-C-O bond in abundantly available biomass-based furfural and its derivatives provides a viable route for sustainable synthesis of valuable C5 compounds, particularly with two terminal oxygen-containing functional groups. However, efficient cleavage of this bond under mild conditions still remains a crucial challenge, primarily because of the competing cleavage of the α-C-O bond and hydrogenation of furan ring. Here, we report that supported Pt catalysts were extremely active for the selective α-C-O cleavage in 2-furancarboxylic acid (FCA) hydrogenolysis to synthesize 5-hydroxyvaleric acid (5-HVA), affording a high yield (～78%) on Pt/SiO2 with a Pt particle size of 4.2 nm at an unprecedentedly low temperature of 313 K. In this reaction, the turnover rate and 5-HVA selectivity sensitively depend on the size of the Pt nanoparticles and the underlying support, as a consequence of their effects on the exposed Pt surfaces. Combined reaction kinetic, infrared spectroscopic, and theoretical assessments reveal that while the exposed high-index Pt surfaces (containing higher fraction of step sites) facilitate the kinetically relevant addition of the first H atom to the unsaturated C atom in furan ring and thus the hydrogenolysis activity, the low-index surfaces (containing higher fraction of terrace sites), together with the electron-withdrawing effect of the carboxylic substituent in FCA, favorably stabilize the dangling C2 atom in the transition states of α-C-O cleavage and lower their activation barriers, leading to the observed high 5-HVA selectivity. Such pivotal roles of the intrinsic properties of metal surfaces and substituents in tuning the reaction pathways will provide a viable strategy for highly selective upgrading of furan derivatives and other biomass-based oxygenates.
