Transition-metal-free synthesis of pyrimidines from lignin β-O-4 segments via a one-pot multi-component reaction

Abstract

Heteroatom-participated lignin depolymerization for heterocyclic aromatic compounds production is of great importance to expanding the product portfolio and meeting value-added biorefinery demand, but it is also particularly challenging. In this work, the synthesis of pyrimidines from lignin β-O-4 model compounds, the most abundant segment in lignin, mediated by NaOH through a one-pot multi-component cascade reaction is reported. Mechanism study suggests that the transformation starts by NaOH-induced deprotonation of Cα-H bond in β-O-4 model compounds, and involves highly coupled sequential cleavage of C-O bonds, alcohol dehydrogenation, aldol condensation, and dehydrogenative aromatization. This strategy features transition-metal free catalysis, a sustainable universal approach, no need of external oxidant/reductant, and an efficient one-pot process, thus providing an unprecedented opportunity for N-containing aromatic heterocyclic compounds synthesis from biorenewable feedstock. With this protocol, an important marine alkaloid meridianin derivative can be synthesized, emphasizing the application feasibility in pharmaceutical synthesis.

Fabrication of Carboxylic Acid and Imidazolium Ionic Liquid Functionalized Porous Cellulosic Materials for the Efficient Conversion of Carbon Dioxide into Cyclic Carbonates

“…Conversion of biomass into high value-added chemicals and sustainable materials has become a hot topic, − among which the design and preparation of cellulose-PILs have received great attention. The preparation of cellulose-PILs is mainly achieved by reaction of cellulose’s hydroxyl groups.…”

Chemical transformations of 5-hydroxymethylfurfural into highly added value products: present and future

“…Although significant progress has been achieved for the upgrading of HMF, some issues still remain: (1) The rational design of cost-effective high-performance catalysts with Earth abundance is highly desired. (2) One-step upgrading of HMF into the target products is highly desired, especially for a process without separation and purification of reaction intermediates.…”

“…The fluctuating supply of costly fossil fuels and their environmental effects have forced society to search for more sustainable sources of energy such as hydroelectricity, wind, solar and biomass. 1,2 Plant-derived biomass represents the only sustainable carbon neutral source with an abundance similar to petroleum-based sources. 3,4 Plant biomass-based energy and chemicals not only provide local heat and power, but also give impetus to the local economy and increase the energy independence of communities using existing infrastructure (fuel processing, vehicles, CHP).…”

Hybridization of CuO with BiVO4 as an Efficient and Stable Photocatalyst for Selective Cleavage of Lignin C–C Bonds

“…Therefore, specific dissociation of these robust interlinkages is needed to obtain high-additive-value chemicals . Much effort has been devoted to using advanced techniques for cleaving C–O or C–C bonds, − including acid catalysis, pyrolysis, gasification, hydrogenolysis, redox-neutral strategy without the use of extra oxidants or reductants, and N-participated depolymerization to produce value-added products. However, bond-breaking in bond dissociation energy for C–C bonds ranges from 226 to 494 kJ/mol, which is more energetic than the C–O bonds (209–348 kJ/mol) .…”