13019-16-4Relevant academic research and scientific papers
Guerbet Alcohols: From Processes under Harsh Conditions to Synthesis at Room Temperature under Ambient Pressure
Biermann, Marc,Gru?, Hendrik,Hummel, Werner,Gr?ger, Harald
, p. 895 - 899 (2016)
A novel synthetic approach towards Guerbet alcohols, which are important intermediates in the production of plasticizers, lubricants, and surfactants, was developed. In contrast to the harsh reaction conditions of Guerbet alcohols produced today, which include high temperatures, the new developed process runs at room temperature. The key feature of this alternative process is the combination of organocatalytic and enzymatic steps towards a chemoenzymatic synthesis. In detail, the piperidinyloxyl-catalyzed oxidation of 1-hexanol by using hypochlorite and the lysine-catalyzed homoaldol condensation of the resulting aldehyde were combined with two subsequent enzymatic reductions of the C=C and C=O bonds of the in situ formed 2-branched α,β-unsaturated aldehyde by means of an ene reductase from Gluconobacter oxydans and an alcohol dehydrogenase from Rhodococcus sp. under in situ cofactor regeneration. The desired 2-branched aliphatic primary alcohol was obtained with high conversion and selectivity and without the need for intermediate purifications. Fantastic four: The synthesis of Guerbet alcohols at room temperature under ambient pressure is reported; this is in contrast to today's industrial production, which is performed under harsh reaction conditions. The presented process is based on the combination of two organocatalytic steps with a biocatalytic two-step tandem process starting from readily available aliphatic alcohols. High conversions and selectivities are found for all steps.
Synthesis of Guerbet ionic liquids and extractants as β-branched biosourceable hydrophobes
Damilano, Giacomo,Binnemans, Koen,Dehaen, Wim
, p. 9778 - 9791 (2019)
This study investigates the synthesis of β-branched amines and β-branched quaternary ammonium chloride ionic liquids as novel extractants. The synthesis methodology was tailored to facilitate the reaction scale-up and the use of biorenewable starting materials. The developed process is an overall green, easy and straightforward synthesis of β-branched amines, and ammonium salts, starting from linear aldehydes. In order to evaluate the potential of the synthesised materials in applications, the rheology, density, thermal stability, chemical stability, phase transitions, and mutual solubility with water of the novel extractants was studied.
A comprehensive investigation and optimisation on the proteinogenic amino acid catalysed homo aldol condensation
Ostrowski, Karoline A.,Lichte, Dominik,Stuck, Moritz,Vorholt, Andreas J.
, p. 592 - 598 (2016)
A systematic investigation regarding the application of catalytic amounts of all 20 proteinogenic amino acids in the homo aldol condensation of aldehydes is described obtaining excellent yields of the desired α,β-unsaturated aldehyde. These investigations
Chichibabin pyridinium synthesis
Imura, Akiho,Tanaka, Nao,Usuki, Toyonobu
, p. 489 - 492 (2019)
Chichibabin pyridine synthesis involves the reaction of three aldehydes and ammonia to form 2,3,5-trisubstituted pyridines. This study examined the synthesis of tetrasubstituted pyridinium from aldehydes and an amine hydrochloride in the presence/absence of Pr(OTf)3. Important insights into the reaction mechanisms of Chichibabin pyridinium synthesis were proposed through the investigation of reaction intermediates along with quantitative GC–MS analysis.
The construction of novel and efficient hafnium catalysts using naturally existing tannic acid for Meerwein-Ponndorf-Verley reduction
Deng, Lijuan,Hao, Jianxiu,He, Runxia,Li, Na,Liu, Quansheng,Wang, Xiaolu,Zhao, Hongye,Zhi, Keduan,Zhou, Huacong
, p. 6944 - 6952 (2020/03/03)
The conversion of carbonyl compounds into alcohols or their derivatives via the catalytic transfer hydrogenation (CTH) process known as Meerwein-Ponndorf-Verley reduction is an important reaction in the reaction chain involved in biomass transformation. The rational design of efficient catalysts using natural and renewable materials is critical for decreasing the catalyst cost and for the sustainable supply of raw materials during catalyst preparation. In this study, a novel hafnium-based catalyst was constructed using naturally existing tannic acid as the ligand. The prepared hafnium-tannic acid (Hf-TA) catalyst was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and thermogravimetry (TG). Hf-TA was applied in the conversion of furfuraldehyde (FD) to furfuryl alcohol (FA) using isopropanol (2-PrOH) as both the reaction solvent and the hydrogen source. Both preparation conditions and the effects of the reaction parameters on the performance of the catalyst were studied. Under the relatively mild reaction conditions of 70 °C and 3 h, FD (1 mmol) could be converted into FA with a high yield of 99.0%. In addition, the Hf-TA catalyst could be reused at least ten times without a notable decrease in activity and selectivity, indicating its excellent stability. It was proved that Hf-TA could also catalyze the conversion of various carbonyl compounds with different structures. The high efficiency, natural occurrence of tannic acid, and facile preparation process make Hf-TA a potential catalyst for applications in the biomass conversion field.
Acid Catalysts Based on Mesoporous Aromatic Frameworks in Aldol Condensation of Furfural with Some Carbonyl Compounds
Talanova, M. Yu.,Yarchak,Karakhanov
, p. 857 - 864 (2019/08/12)
Aldol condensation of furfural with acetone and a series of aldehydes in the presence of PAF-SO3H acid catalyst based on mesoporous aromatic frameworks was investigated. The reaction course depending on the process temperature, catalyst amount, and reactant ratio was considered for the furfural condensation with acetone as an example. The catalyst can be reused in several cycles without appreciable activity loss.
CONVERSION OF ALCOHOLS TO LINEAR AND BRANCHED FUNCTIONALIZED ALKANES
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Page/Page column 10-11, (2018/03/09)
Embodiments herein concerns the eco-friendly conversion of simple alcohols to linear or branched functionalized alkanes, by integrated catalysis. The alcohols are firstlyoxidized either chemically or enzymatically to the corresponding aldehydes or ketones, followed by aldol condensations using a catalyst to give the corresponding enals or enones. The enals or enones are subsequently and selectively hydrogenated using a recyclable heterogeneous metal catalyst, organocatalyst or an enzyme to provide linear or branched functionalized alkanes with an aldehyde, keto- or alcohol functionality. The process is also iterative and can be further extended by repeating the above integrated catalysis for producing long-chain functionalized alkanes from simple alcohols.
Synthesizing method of 2-butyl-1-octanol
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Paragraph 0026-0027, (2018/07/15)
The invention discloses a synthesizing method of 2-butyl-1-octanol. The method includes the following steps of conducting an aldol condensation reaction with n-caproaldehyde as the initiator to obtain2-butyl-2-octenal, wherein a catalyst in the aldol condensation reaction is barium hydroxide; conducting a primary reduction reaction on 2-butyl-2-octenal to obtain a mixture of aldehyde and alcohol,and conducting a secondary reduction reaction on the mixture of aldehyde and alcohol to obtain 2-butyl-1-octanol, wherein a reducing agent in the primary reduction reaction is palladium on carbon, and a reducing agent in the secondary reduction reaction is sodium borohydride. The method is easy to operate, few byproducts are produced, yield is high, the requirements for devices are not high, andindustrial production is easy.
GUERBET ALCOHOLS AND METHODS FOR PREPARING AND USING SAME
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Paragraph 0097; 0098; 00100; 00101; 00102, (2013/10/08)
The invention relates to Guerbet alcohol precursors and Guerbet alcohols, as well as to processes for synthesizing them.
Rhodium-catalyzed homogeneous reductive amidation of aldehydes
Raoufmoghaddam, Saeed,Drent, Eite,Bouwman, Elisabeth
supporting information, p. 717 - 733 (2013/04/23)
The catalytic reductive amidation of an aldehyde (hexanal) with an amide (acetamide) is reported. Apart from the desired N-hexylacetamide, the two isomeric unsaturated intermediates as well as hexanol are produced together with higher mass products that arise from aldol condensation and diamide coupling of the aldehyde. Screening of different catalyst precursor salts, ligands and reaction conditions led to the finding that the catalytic system based on the (cyclooctadiene)rhodium chloride dimer, [Rh(cod)Cl]2, in combination with the ligand xantphos and an acid co-catalyst results in high selectivity for the desired product. Under optimized conditions nearly full conversion is reached with high selectivity to the desired N-alkylamide and with a very high N-alkylamide/alcohol ratio, while producing only small amounts of by-products. The scope of the reaction has been investigated using different amides as well as aldehydes; the results show the general applicability of this novel reaction, but with electron-withdrawing amides the selectivity to N-alkylamide is lower. NMR studies showed that the nucleophilic addition of acetamide to hexanal is acid catalyzed, forming N-(1-hydroxyhexyl)acetamide in equilibrium with both hexanal and the dehydrated unsaturated imides. A catalytic mechanism is proposed in which a strong acid such as HOTs acts as a co-catalyst by establishing a rapid chemical equilibrium between the aldehyde, acetamide and the intermediates. Furthermore, it is proposed that the presence of acid causes a change in catalytic species, enabling a cationic Rh/xantphos hydrogenation catalyst to selectively hydrogenate the intermediates to N-hexylacetamide in the presence of hexanal. Copyright
