Xn:Harmful;
111-29-5Relevant academic research and scientific papers
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)
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.
One-pot selective conversion of furfural into 1,5-pentanediol over a Pd-added Ir-ReOx/SiO2 bifunctional catalyst
Liu, Sibao,Amada, Yasushi,Tamura, Masazumi,Nakagawa, Yoshinao,Tomishige, Keiichi
, p. 617 - 626 (2014)
One-pot selective conversion of furfural into 1,5-pentanediol (1,5-PeD) was carried out over Pd-added Ir-ReOx/SiO2 catalysts through two-step reaction temperatures. The Pd(0.66 wt%)-Ir-ReOx/SiO 2 catalyst showed the best performance in the production of 1,5-PeD from furfural. The maximum yield of 1,5-PeD was 71.4%. The furfural conversion and yield of 1,5-PeD was almost maintained during four repeated tests when the catalyst was calcined again. The characterization results from TPR, XRD, XANES, EXAFS and FT-IR of adsorbed CO indicated that Pd-Ir-ReOx/SiO 2 catalysts consisted of ReOx-modified Pd metal particles and ReOx-modified Ir metal particles. The lower-temperature reaction step was very crucial for the total hydrogenation of furfural into a tetrahydrofurfuryl alcohol intermediate, which was converted into 1,5-PeD by hydrogenolysis during the high temperature step over the ReOx- modified Ir metal particles.
HOMOGENEOUS CATALYTIC HYDROGENATION OF FREE CARBOXYLIC ACIDS IN THE PRESENCE OF CLUSTER RUTHENIUM CARBONYL HYDRIDES
Bianchi, Mario,Menchi, Gloria,Francalanci, Franco,Piacenti, Franco,Matteoli, Ugo,et al.
, p. 109 - 120 (1980)
Saturated monocarboxylic acids up to C6, several bicarboxylic acids and some of the corresponding anhydrides are hydrogenated in the homogeneous phase with H4Ru4(CO)8(PBu3)4 as catalyst to give the corresponding alcohols (present among the reaction products as esters) or lactones at 100-200 deg C under a pressures of 100-200 atm of hydrogen.Anhydrides react at temperatures lower than those needed for acids.Esters are not reduced.Only δ-valerolactone is hydrogenated to 1,5-pentanediol.Ruthenium carbonyl carboxylates have been recovered at the end of the reaction andappear to be catalytically active intermediates.
One-pot biosynthesis of 1,6-hexanediol from cyclohexane by: De novo designed cascade biocatalysis
Kang, Lixin,Li, Aitao,Li, Qian,Li, Renjie,Wang, Fei,Yu, Xiaojuan,Zhang, Zhongwei,Zhao, Jing
, p. 7476 - 7483 (2020)
1,6-Hexanediol (HDO) is an important precursor in the polymer industry. The current industrial route to produce HDO involves energy intensive and hazardous multistage (four-pot-four-step) chemical reactions using cyclohexane (CH) as the starting material, which leads to serious environmental problems. Here, we report the development of a biocatalytic cascade process for the biotransformation of CH to HDO under mild conditions in a one-pot-one-step manner. This cascade biocatalysis operates by using a microbial consortium composed of three E. coli cell modules, each containing the necessary enzymes. The cell modules with assigned functions were engineered in parallel, followed by combination to construct E. coli consortia for use in biotransformations. The engineered E. coli consortia, which contained the corresponding cell modules, efficiently converted not only CH or cyclohexanol to HDO, but also other cycloalkanes or cycloalkanols to related dihydric alcohols. In conclusion, the newly developed biocatalytic process provides a promising alternative to the current industrial process for manufacturing HDO and related dihydric alcohols. This journal is
HYDROGENATION OF FURFURAL ON POLYMER-CONTAINING CATALYSTS
Karakhanov, E. A.,Neimerovets, E. B.,Pshezhetskii, V. S.,Dedov, A. G.
, p. 243 - 246 (1986)
The catalytic hydrogenation of furfural with molecular hydrogen has been investigated under mild conditions in the presence of metal complex catalysts with a polymeric macroligand.It has been shown that the reaction proceeds according to a consecutive scheme with the formation of furfuryl and tetrahydrofurfuryl alcohols.The kinetics of furfural hydrogenation has been investigated and the order of the reaction established; the rate constants of the first and second stages have been determined.The influence of the solvent and of the metal-to-polymer ratio on the furfural conversion have been investigated.
RING CLEAVAGE REARRANGEMENT OF CYCLOBUTYLMETHYLBORANES
Hill. E. Alexander,Nylen, Patricia A.,Fellinger, John H.
, p. 279 - 292 (1982)
Boranes derived from hydroboration of methylenecyclobutane with borane/THF, 9-borabicyclononane, and borane-methyl sulfide rearranged on heating in situ at 100-160 deg C to open chain structures.Products after oxidation were the unrearranged cyclobutylmethanol, and 4-penten-1-ol, 1,4-pentane-diol and 1,5-pentanediol.The unsaturated alcohol was the major product in reactions with a stoichiometric ratio of alkene to BH bonds, and the diols were formed with excess borane.With borane-methyl sulfide as hydroborating reagent, the rate of rearrangement at 100 deg C in triglyme was not significantly dependent upon the initial alkene/borane ratio (3/1 or 1.15/1) or the presence of excess methyl sulfide.However, an equivalent amount of pyridine prevented rearrangement.Rearrangement in THF using borane/THF also occurred at comparable rates in the presence and absence of excess borane.Little or no isomerization of the boron function into the cyclobutane ring was observed.Results are interpreted on the basis of a concerted four-center mechanism which requires a vacant boron orbital.
Promoting effect of Mo on the hydrogenolysis of tetrahydrofurfuryl alcohol to 1,5-pentanediol over Rh/SiO2
Koso, Shuichi,Ueda, Naoyuki,Shinmi, Yasunori,Okumura, Kazu,Kizuka, Tokushi,Tomishige, Keiichi
, p. 89 - 92 (2009)
Addition of Mo to Rh/SiO2 promoted the hydrogenolysis of tetrahydrofurfuryl alcohol to 1,5-pentanediol drastically. Addition of Re and W to Rh/SiO2 was also effective, but the promoting effect of Mo was more remarkable in terms of ca
One-pot selective conversion of C5-furan into 1,4-pentanediol over bulk Ni-Sn alloy catalysts in an ethanol/H2O solvent mixture
Rodiansono,Dewi Astuti, Maria,Hara, Takayoshi,Ichikuni, Nobuyuki,Shimazu, Shogo
, p. 2307 - 2315 (2019)
Inexpensive bulk Ni-Sn alloy-based catalysts demonstrated a unique catalytic property in the selective conversion of C5-furan compounds (e.g., furfuraldehyde (FFald), furfuryl alcohol (FFalc), and 2-methylfuran (2-MTF)) in an ethanol/H2O solvent mixture and selectively produced 1,4-pentanediol (1,4-PeD) in a one-pot reaction. The synergistic actions between the bulk Ni-Sn alloy catalyst, hydrogen gas, and the hydroxylated H2O or ethanol/H2O solvents are believed to play a prominent role in the catalytic reactions. Bulk Ni-Sn alloy catalysts that consisted of Ni3Sn or Ni3Sn2 alloy phases allowed an outstanding yield of 1,4-PeD up to 92% (from FFald), 67% (from FFalc), and 48% (from 2-MTF) in ethanol/H2O (1.5:2.0 volume ratio) at 433 K, 3.0 MPa H2 and 12 h. As the reaction temperature increased to 453 K, the yield of 1,4-PeD slightly decreased to 87% (from FFald), whereas it slightly increased to 71% (from FFalc). The bulk Ni-Sn alloy catalysts were reusable without any significant loss of selectivity.
Selective Activation of C-OH, C-O-C, or Ca? C in Furfuryl Alcohol by Engineered Pt Sites Supported on Layered Double Oxides
An, Zhe,He, Jing,Jiang, Yitao,Ma, Xiaodan,Shu, Xin,Song, Hongyan,Xiang, Xu,Zhang, Jian,Zhang, Zhijun,Zhao, Wenfang,Zheng, Lirong,Zhu, Yanru
, p. 8032 - 8041 (2020)
The selective activation of targeted bonds in biomass-derived furfural or furfuryl alcohol with complex chemical linkages (C-C/C-H/C-O, Ca? C/Ca? O, or C-O-H/C-O-C) is of great challenge for biomass upgrading, expecting well-defined catalyst and definite catalytically active sites. This work demonstrates an efficient targeted activation to C-OH, C-O-C, or Ca? C by engineering the structure of catalytic Pt sites, affording 2-methylfuran (2-MF), tetrahydrofurfuryl alcohol (THFA), or 1,2-pentanediol (1,2-PeD) as product in the hydroconversion of furfuryl alcohol. The catalytic Pt sites have been engineered as atomic Pt, coordination unsaturated Pt-Pt in atom-thick dispersion, or coordination unsaturated 3D Pt-Pt by tailoring the Pt dispersion (single atom, 2D cluster, or 3D cluster) on Mg and Al-containing layered double oxide (Mg(Al)O) support. The selective activation of C-OH, C-O-C, or Ca? C has been traced with the FT-IR spectra recorded surface reaction. On atomic Pt, C-O-H is easily activated, with the assistance of Mg(Al)O support, with O-terminal adsorption without affecting furan C-O and Ca? C. However, Ca? C in the furan ring is easier to be activated on coordination-unsaturated Pt-Pt in atom-thick dispersion, resulting in a step-by-step hydrogenation to generate THFA. On coordination-unsaturated 3D Pt-Pt, the hydrogenolysis of furan ring is favored, resulting in the cleavage of furan C-O to produce 1,2-PeD. Also, the Mg(Al)O supports derived from Mg and Al layered double hydroxides (LDHs) here also play a key role in promoting the selectivity to 1,2-PeD by providing basic sites.
Highly Efficient and Convenient Deprotection of Methoxymethyl Ethers and Esters Using Bismuth Triflate in an Aqueous Medium
Venkat Reddy,Jagadeeshwar Rao,Sampath Kumar,Madhusudana Rao
, p. 1038 - 1039 (2003)
A simple and efficient method has been developed for the hydrolysis of methoxymethyl (MOM) ethers and esters to the corresponding alcohols and acids employing a catalytic amount of bismuth triflate in an aqueous medium. The conversions occur at ambient temperature and the yields of the deprotected alcohols are very good. The reaction was highly selective in the presence of other protecting groups such as TBDMS, TBDPS, benzyl, and allyl ethers.
