504-60-9Relevant articles and documents
Production of renewable 1,3-pentadiene over LaPO4 via dehydration of 2,3-pentanediol derived from 2,3-pentanedione
Bai, Chenxi,Cui, Long,Dai, Quanquan,Feng, Ruilin,Liu, Shijun,Qi, Yanlong
, (2022/02/07)
1,3-Pentadiene plays an extremely important role in the production of polymers and fine chemicals. Herein, the LaPO4 catalyst exhibits excellent catalytic performance for the dehydration production of 1,3-pentadiene with 2,3-pentanediol, a C5 diol platform compound that can be easily obtained by hydrogenation of bio-based 2,3-pentanedione. The relationships of catalyst structure-acid/base properties-catalytic performance was established, and an acid-base synergy effect was disclosed for the on-purpose synthesis of 1,3-pentadiene. Thus, a balance between acid and base sites was required, and an optimized LaPO4 with acid/base ratio of 2.63 afforded a yield of 1,3-pentadiene as high as 61.5% at atmospheric pressure. Notably, the Br?nsted acid sites with weak or medium in LaPO4 catalyst can inhibit the occurrence of pinacol rearrangement, resulting in higher 1,3-pentadiene production. In addition, the investigation on reaction pathways demonstrated that the E2 mechanism was dominant in this dehydration reaction, accompanied by the assistance of E1 and E1cb.
Synthesis method of pentanediol, and synthesis method for preparing biomass-based pentadiene through conversion of levulinic acid and derivatives of levulinic acid
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Paragraph 0157; 0161-0165; 0170; 0174-0177; 0178; 0182-0185, (2021/04/07)
The invention provides a synthesis method of pentanediol, and the method comprises the following steps: carrying out conversion reaction on a mixed solution obtained by mixing levulinic acid and/or levulinic acid derivatives, a catalyst and an organic solvent in a hydrogen-containing atmosphere to obtain the pentanediol. According to the method, a large amount of cheap and easily available bio-based chemical levulinic acid or derivatives thereof can be utilized, pentanediol is obtained through catalytic conversion, and m-pentadiene is further obtained. The raw materials are derived from renewable resources, the m-pentadiene is prepared through hydrogenation and dehydration, and particularly, a green and sustainable process route for synthesizing the m-pentadiene is finally obtained through a dehydration reaction route and construction of a dehydration catalyst. The invention provides a method for green and sustainable synthesis of linear pentadiene based on bio-based chemical conversion, and the method has the advantages of simple operation, short flow, no need of harsh experimental conditions, easy preparation of raw materials and catalysts, and large-scale synthesis prospect.
Dehydra-decyclization of 2-methyltetrahydrofuran to pentadienes on boron-containing zeolites
Dauenhauer, Paul J.,Kumar, Gaurav,Liu, Dongxia,Ren, Limin,Tsapatsis, Michael,Xu, Dandan
supporting information, p. 4147 - 4160 (2020/07/14)
1,3-Pentadiene (piperylene) is an important monomer in the manufacturing of adhesives, plastics, and resins. It can be derived from biomass by the tandem ring-opening and dehydration (dehydra-decyclization) of 2-methyltetrahydrofuran (2-MTHF), but competing reaction pathways and the formation of another isomer (1,4-pentadiene) have limited piperylene yields to MFI > BEA at a given temperature (523 K), indicating the non-identical nature of active sites in these weak solid acids. The diene distribution remained far from equilibrium and was tuned towards the desirable conjugated diene (1,3-pentadiene) by facile isomerization of 1,4-pentadiene. This tuning capability was facilitated by high bed residence times, as well as the smaller micropore sizes among the zeolite frameworks considered. The suppression of competing pathways, and promotion of 1,4-pentadiene isomerization events lead to a hitherto unreported ~86percent 1,3-pentadiene yield and an overall ~89percent combined linear C5 dienes' yield at near quantitative (~98percent) 2-MTHF conversion on the borosilicate B-MWW, without a significant reduction in diene selectivities for at least 80 hours time-on-stream under low space velocity (0.85 g reactant per g cat. per h) and high temperature (658 K) conditions. Finally, starting with iso-conversion levels (ca. 21-26percent) and using total turnover numbers (TONs) accrued over the entire catalyst lifetime as the stability criterion, borosilicates were demonstrated to be significantly more stable than aluminosilicates under reaction conditions (~3-6× higher TONs).