19481-10-8

Upstream product

• 609-14-3 2-acetylpropanoic acid ethyl ester 
• 274-09-9 Methylenedioxybenzene 
• 2171-74-6 1,3-benzodioxol-2-one 
• 95-53-4 o-toluidine 
• 99-50-3 3,4-Dihydroxybenzoic acid 
• 123-51-3 i-Amyl alcohol 
• 643-94-7 o-phenylene dibenzoate 
• 5435-44-9 (E)-3-Ureido-but-2-enoic acid ethyl ester 
• 492-89-7 3-pentadecylcatechol 
• 95-57-8 2-monochlorophenol 
• 95-56-7 2-hydroxybromobenzene 
• 35580-89-3 ethyl-carbamic acid-(2-hydroxy-phenyl ester) 
• 583-63-1 ortoquinone 
• 56-23-5 tetrachloromethane 

Downstream Products

• 105263-56-7 1-(2,3-dihydroxy-phenyl)-pyridinium; bromide 
• 855471-08-8 3,6-dichloro-2-(3,4-dihydroxy-benzoyl)-benzoic acid 
• 7402-27-9 1,2-bis(propanoyloxy)benzene 
• 50835-95-5 ethyl 2-(2-methylbenzo[d][1,3]dioxol-2-yl)acetate 
• 57878-33-8 4-cyclopent-2-enyl-pyrocatechol 
• 30725-06-5 4,5-Di-(p-chloranilino)-1,2-benzochinon 
• 67655-19-0 1,3-bis-(2-hydroxy-phenoxy)-propan-2-ol 
• 91364-06-6 ortho-hydroxyphenyl 2,3,4,6-tetra-O-acetyl-β-D-glucopyranoside 
• 898283-47-1 1,2-Bis-(2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyloxy)benzene 
• 69305-39-1 3',4'-dimethyl-2-phenyl-2',5'-dihydro-1'H-2λ⁵-spiro[benzo[1,3,2]dioxaphosphole-2,1'-phosphole] 
• 52341-78-3 2,2-dioxo-4-phenyl-2,3,4,5-tetrahydro-2λ⁶-benzo[h][1,7,2,3]dioxathiazonin-6-one 
• 26071-86-3 2,2'-(2-phenyl-ethene-1,1-diyl)-bis-benzo[1,3,2]dioxaborole 
• 68281-26-5 3,4-dihydro-3-methyl-2H-1,5-benzodioxepin-3-ol 
• 16163-78-3 2,3-dihydro-2-methyl-1,4-benzodioxin-2-methyl 4-tolylsulfonate 

Relevant academic research and scientific papers

Multi-Enzymatic Cascade Reactions for the Synthesis of cis,cis-Muconic Acid

Lignin valorization allows the generation of a number of value-added products such as cis,cis-muconic acid (ccMA), which is widely used for the synthesis of chemicals for the production of biodegradable plastic materials. In the present work, we reported the first multi-enzymatic, one-pot bioconversion process of vanillin into ccMA. In details, we used four sequential reactions catalyzed by xanthine oxidase, O-demethylase LigM (and the tetrahydrofolate-regeneration enzyme methyl transferase MetE), decarboxylase AroY (based on the use of E. coli transformed cells) and catechol 1,2-dioxygenase CatA. The optimized lab-scale procedure allowed to reach, for the first time, the conversion of 5 mM vanillin into ccMA in ～30 h with a 90% yield: this achievement represents an improvement in terms of yields and time when compared to the use of a whole-cell system. This multi-enzymatic system represents a sustainable alternative for the production of a high value added product from a renewable resource. (Figure presented.).

Imidazolium-urea low transition temperature mixtures for the UHP-promoted oxidation of boron compounds

Different carboxy-functionalized imidazolium salts have been considered as components of low transition temperature mixtures (LTTMs) in combination with urea. Among them, a novel LTTM based on 1-(methoxycarbonyl)methyl-3-methylimidazolium chloride and urea has been prepared and characterized by differential scanning calorimetry throughout its entire composition range. This LTTM has been employed for the oxidation of boron reagents using urea-hydrogen peroxide adduct (UHP) as the oxidizer, thus avoiding the use of aqueous H2O2, which is dangerous to handle. This metal-free protocol affords the corresponding alcohols in good to quantitative yields in up to 5 mmol scale without the need of further purification. The broad composition range of the LTTM allows for the reaction to be carried out up to three consecutive times with a single imidazolium salt loading offering remarkable sustainability with an E-factor of 7.9, which can be reduced to 3.2 by the threefold reuse of the system.

The role of remote flavin adenine dinucleotide pieces in the oxidative decarboxylation catalyzed by salicylate hydroxylase

Salicylate hydroxylase (NahG) has a single redox site in which FAD is reduced by NADH, the O2 is activated by the reduced flavin, and salicylate undergoes an oxidative decarboxylation by a C(4a)-hydroperoxyflavin intermediate to give catechol. We report experimental results that show the contribution of individual pieces of the FAD cofactor to the observed enzymatic activity for turnover of the whole cofactor. A comparison of the kinetic parameters and products for the NahG-catalyzed reactions of FMN and riboflavin cofactor fragments reveal that the adenosine monophosphate (AMP) and ribitol phosphate pieces of FAD act to anchor the flavin to the enzyme and to direct the partitioning of the C(4a)-hydroperoxyflavin reaction intermediate towards hydroxylation of salicylate. The addition of AMP or ribitol phosphate pieces to solutions of the truncated flavins results in a partial restoration of the enzymatic activity lost upon truncation of FAD, and the pieces direct the reaction of the C(4a)-hydroperoxyflavin intermediate towards hydroxylation of salicylate.

High-throughput assay of tyrosine phenol-lyase activity using a cascade of enzymatic reactions

Tyrosine phenol-lyase (TPL) exhibits great potential in industrial biosynthesis of L-tyrosine and its derivates. To uncover and screen TPLs with excellent catalytic properties, there is unmet demand for development of facile and reliable screening system for TPL. Here we presented a novel assay format for the detection of TPL activity based on catechol 2,3-dioxygenase (C23O)-catalyzed reaction. Catechol released from TPL-catalyzed cleavage of 3,4-dihydroxy-L-phenylalanine (L-DOPA) was further oxidized by C23O to form 2-hydroxymuconate semialdehyde, which could be readily detected by spectrophotometric measurements at 375 nm. The assay achieved a unique balance between the ease of operation and superiority of analytical performances including linearity, sensitivity and accuracy. In addition, this assay enabled real-time monitoring of TPL activity with high efficiency and reliability. As C23O is highly specific towards catechol, a non-natural product of microorganism, the assay was therefore accessible to both crude cell extracts and the whole-cell system without elaborate purification steps of enzymes, which could greatly expedite discovery and engineering of TPLs. This study provided fundamental principle for high-throughput screening of other enzymes consuming or producing catechol derivatives.

One-pot production of phenazine from lignin-derived catechol

Upgrading lignin-derived monomeric products is crucial in bio-refineries to effectively utilize lignin. Herein, we report a simple strategy to convert catechol to phenazine, a useful N-heterocycle three-aromatic-ring compound, whose current synthetic procedure is complex via a petroleum-derived feedstock. The reaction uses catechol as the sole carbon source and aqueous ammonia as reaction media and a nitrogen source. Without additional solvents, phenazine was obtained in 67% yield in the form of high purity crystals (>97%) over a Pd/C catalyst after a one-pot-two-stage reaction. When cyclohexane was used as a co-solvent in the first step, a higher yield (81%) and purity (>99%) were achieved. Mechanistic investigations involving control experiments and an isotope labeling study reveal that hydrogenation, amination, coupling and dehydrogenation reactions are the key steps leading to phenazine formation. The conversion of other lignin-derived catechols highlights that the protocol is extendable to produce substituted phenazines.

Me3SI-promoted chemoselective deacetylation: a general and mild protocol

A Me3SI-mediated simple and efficient protocol for the chemoselective deprotection of acetyl groups has been developedviaemploying KMnO4as an additive. This chemoselective deacetylation is amenable to a wide range of substrates, tolerating diverse and sensitive functional groups in carbohydrates, amino acids, natural products, heterocycles, and general scaffolds. The protocol is attractive because it uses an environmentally benign reagent system to perform quantitative and clean transformations under ambient conditions.

Heterogeneous recyclable copper oxide supported on activated red mud as an efficient and stable catalyst for the one pot hydroxylation of benzene to phenol

Phenol is a key intermediate in chemical industry. The present research work reports facile synthesis of a new copper supported activated red mud as a heterogeneous catalyst for oxidative conversion of benzene to phenol. The process is simple and efficient for one pot hydroxylation reaction using H2O2 as an oxidant. The catalyst was characterized using FTIR, XRD, TEM, XPS and BET surface area analyzer. Catalyst reducible properties were studied using H2-TPR technique. The one-pot hydroxylation reaction, carried out at 75 °C under optimum reaction conditions in presence of catalytic material, shows conversion of benzene to phenol with 84.5 % and 87.1 % selectivity and conversion efficiency, respectively. The proposed mechanism emphasizes upon cooperative effect of residual and embedded metal ions in solid catalyst matrix as the contributing factor for efficient conversion and selectivity. The reusable properties of the material, tested up to 5th consecutive cycles of batch operation, indicate retention of selectivity (83.9 %) as well as conversion efficiency (86.7 %), suitable for future commercial development adhering to the principle of green chemistry.

Highly efficient titanosilicate catalyst Ti-MCM-68 prepared using a liquid-phase titanium source for the phenol oxidation

A highly efficient Ti-MCM-68 catalyst for phenol oxidation with H2O2 was prepared by a mild liquid-phase treatment for the first time. The key preparation procedures to excellent catalytic activity and high para-selectivity were the use of aqueous solutions of the Ti source and calcination at 650 °C prior to catalytic use.

Preparation and photocatalytic performance of silver-modified and nitrogen-doped TiO2nanomaterials with oxygen vacancies

The photocatalysis of titanium dioxide (TiO2) exerts excellent degradation performance against contaminants in the environment. However, it prefers to absorb ultraviolet light rather than visible light, which significantly constrains its widespread use under visible light. Here, we prepared oxygen vacancy-containing TiO2viaAg-modification and N-doping. The utilization of visible light for phenol degradation was significantly enhanced by Ag/N co-doping. The characterization results showed a shuttle-like material coupled with multiple oxygen vacancies, and a well-designed experiment demonstrated that the Ti?:?N?:?Ag ratio of 1?:?0.45?:?0.32 presented optimal performance for phenol degradation. The batch experiment results also proved the modified TiO2as a potent photocatalyst against phenol degradation with an 80.8% degradation efficiency within 5 hours under visible light and with a 99.3% degradation efficiency within 2 hours under ultraviolet light. What is more, we also demonstrated that hydroxyl radical was the mainly effective radical in the mineralization of phenol and put forward a possible degradation pathway based on the observed intermediates. Lastly, the cycling tests indicated that the proposed photocatalyst is durable with a fair phenol degradation ability after recycling 5 times.

A high-nuclearity CuI/CuIInanocluster catalyst for phenol degradation

Herein, we report a 54-nuclei copper nanocluster, [Cu54S13O6(tBuS)20(tBuSO3)12] (Cu54), which is the largest atom-precise CuI/CuIImix-valent cluster reported. The Cu54nanoclusters supported by TiO2exhibit decent photocatalytic activity for phenol degradation under visible light. This work provides a platform to explore the catalytic behaviors of CuI/CuIInanosystems.