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Production of renewable 1,3-pentadiene over LaPO4 via dehydration of 2,3-pentanediol derived from 2,3-pentanedione
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.
Bai, Chenxi,Cui, Long,Dai, Quanquan,Feng, Ruilin,Liu, Shijun,Qi, Yanlong
(2022/02/07)

Highly regioselective homogeneous isomerization-hydroformylation of 2-butene with water- and air-stable phosphoramidite bidentate ligand
Highly selective isomerization-hydroformylation of 2-butene was achieved with the presence of Rh(acac)(CO)2 and a phosphoramidite bidentate ligand which bearing 2,2′-dihydroxy-1,1′-binaphthyl backbone and N-indolyl substitute. The molar ratio of n- to isovaleraldehyde (217) is distinctly higher than the reported systems. NMR and IR revealed that the five-coordinate HRh(ligand)(CO)2 was an equatorial-equatorial configuration which contributed to the n-selectivity of valeraldehyde. The strong π-acceptor ability of ligand was suggested to play a key role in fast isomerization of 2-butene. Hydrolysis and oxidation experiments demonstrated that the ligand was water- and air-stable. Cyclic voltammetry measurement confirmed that this phosphoramidite ligand is more difficult to be oxidized, compared with the phosphine, phosphinite and phosphite ligands. Inspiringly, recycling experiments showed the catalytic system could work for at least 7 runs with unchanged selectivity.
Tang, Songbai,Jiang, Yanxin,Yi, Jiwei,Duan, Xiaoxia,Fu, Haiyan,Li, Ruixiang,Yuan, Maolin,Chen, Hua,Yang, Chunji,Zheng, Xueli
(2021/05/10)

MANUFACTURING METHOD FOR THE ALDEHYDE BY HYDROFORMYLATION REACTION
A phosphine ligand represented by chemical formula 1. Transition metal catalyst A hydroformylation catalyst composition comprising a solvent and a solvent. Provided is a process for preparing aldehydes by hydroformylation using olefinic compounds and formaldehyde to produce aldehydes.
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Paragraph 0079-0081; 0083-0084; 0101

(2021/07/13)

Ligand coordination sphere effect of Schiff base cis-dioxomolybdenum(VI) complexes in selective catalytic oxidation of alcohols
Several cis-dioxomolybdenum(VI) complexes with Schiff bases-derived ligands were synthesized and fully characterized. The catalytic performances of these complexes were tested in the alcohol oxidation under solvent-free condition using H2O2 as oxidant giving high results. The influence of the oxygen, sulfur, and nitrogen atom within the coordination sphere around the molybdenum center was studied (S?>?N?>?O). From this study, we suggest that there exists a relationship between the electronegativity of the atom and the catalytic performance in alcohol oxidation.
Liu, Haiwen,Zhuo, Zihan,Zhang, Yan,Wei, Hang,Zhang, Wenxin,Li, Tong,Mao, Zuodong,Wang, Weili
p. 1253 - 1261
(2021/08/13)

Synthesis of Chiral Amines via a Bi-Enzymatic Cascade Using an Ene-Reductase and Amine Dehydrogenase
Access to chiral amines with more than one stereocentre remains challenging, although an increasing number of methods are emerging. Here we developed a proof-of-concept bi-enzymatic cascade, consisting of an ene reductase and amine dehydrogenase (AmDH), to afford chiral diastereomerically enriched amines in one pot. The asymmetric reduction of unsaturated ketones and aldehydes by ene reductases from the Old Yellow Enzyme family (OYE) was adapted to reaction conditions for the reductive amination by amine dehydrogenases. By studying the substrate profiles of both reported biocatalysts, thirteen unsaturated carbonyl substrates were assayed against the best duo OYE/AmDH. Low (5 %) to high (97 %) conversion rates were obtained with enantiomeric and diastereomeric excess of up to 99 %. We expect our established bi-enzymatic cascade to allow access to chiral amines with both high enantiomeric and diastereomeric excess from varying alkene substrates depending on the combination of enzymes.
Fossey-Jouenne, Aurélie,Jongkind, Ewald P. J.,Mayol, Ombeline,Paul, Caroline E.,Vergne-Vaxelaire, Carine,Zaparucha, Anne
(2021/12/23)

An In-Situ Self-regeneration Catalyst for the Production of Renewable Penta-1,3-diene
Catalyst deactivation is a problem of great concern for many heterogeneous reactions. Here, an urchin-like LaPO4 catalyst was easily developed for pentane-2,3-diol dehydration; it has an impressive ability to restore the activity in situ by itself during the reaction, accounting for its high stability. This facilitates the efficient production of renewable penta-1,3-diene from pentane-2,3-dione via a novel approach, where penta-2,3-diol was obtained as an intermediate in 95 % yield under mild conditions.
Feng, Ruilin,Qi, Yanlong,Liu, Shijun,Cui, Long,Dai, Quanquan,Bai, Chenxi
supporting information
p. 9495 - 9498
(2021/05/27)

Chemo- And regioselective hydroformylation of alkenes with CO2/H2over a bifunctional catalyst
As is well known, CO2 is an attractive renewable C1 resource and H2 is a cheap and clean reductant. Combining CO2 and H2 to prepare building blocks for high-value-added products is an attractive yet challenging topic in green chemistry. A general and selective rhodium-catalyzed hydroformylation of alkenes using CO2/H2 as a syngas surrogate is described here. With this protocol, the desired aldehydes can be obtained in up to 97% yield with 93/7 regioselectivity under mild reaction conditions (25 bar and 80 °C). The key to success is the use of a bifunctional Rh/PTA catalyst (PTA: 1,3,5-triaza-7-phosphaadamantane), which facilitates both CO2 hydrogenation and hydroformylation. Notably, monodentate PTA exhibited better activity and regioselectivity than common bidentate ligands, which might be ascribed to its built-in basic site and tris-chelated mode. Mechanistic studies indicate that the transformation proceeds through cascade steps, involving free HCOOH production through CO2 hydrogenation, fast release of CO, and rhodium-catalyzed conventional hydroformylation. Moreover, the unconventional hydroformylation pathway, in which HCOOAc acts as a direct C1 source, has also been proved to be feasible with superior regioselectivity to that of the CO pathway.
Hua, Kaimin,Liu, Xiaofang,Wei, Baiyin,Shao, Zilong,Deng, Yuchao,Zhong, Liangshu,Wang, Hui,Sun, Yuhan
supporting information
p. 8040 - 8046
(2021/11/01)

Method for synthesizing fluorescent dye intermediate aldehyde by hydroformylation of 1,3-diene compound
The invention discloses a method for synthesizing a fluorescent dye intermediate aldehyde by hydroformylation of 1,3-diene compound. The method comprises the following steps: S1, sequentially adding 0.01 mmol (1 mol%) of [Rh(cod)Cl]2, 0.1 mmol of a phosphine ligand(P/Rh=10/1) and 1 mmol of diene into a reaction flask, adding 1 ml of a solvent DMF, putting the reaction flask into a high-pressure reaction kettle, after the reaction is finished, transferring a mixed solution into a 25 mL glass bottle with 200 microliters of n-tridecane as an internal standard by using a rubber head dropper, and detecting; and S2, determining the product yield and the structure through a gas chromatograph and a nuclear magnetic resonance spectrum, wherein the obtained olefin conversion rate is larger than 99%, the aldehyde yield ranges from 61% to 99%, and the regioselectivity of the product aldehyde ranges from 70/30 to 100/0. According to the method disclosed by the invention, the separation and purification steps of aldehyde products are simplified, and the substrate of the dialkene hydroformylation reaction is excellent in universality.
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Paragraph 0053-0054; 0056-0057

(2021/08/07)

Synthesis of Enantioenriched Amines by Iron-Catalysed Amination of Alcohols Employing at Least One Achiral Substrate
The synthesis of a broad range of enantioenriched amines by the direct Fe-catalysed coupling of amines with alcohols through the borrowing hydrogen strategy, while at least one of these substrates is achiral is reported. When starting from α-chiral amines and achiral alcohols, a wide range of enantioenriched amine products, including N-heterocyclic moieties can be obtained with complete retention of stereochemistry and the power of this method is demonstrated in the one-step synthesis of known pharmaceuticals from commercially available, simple enantiopure primary amines and achiral alcohols. It was also found that the use of β-branched enantioenriched primary alcohols and achiral amines as reaction partners leads to a partial loss of stereochemical integrity in the final product, however, a systematic optimization enabled partial retention of enantiopurity and possible parameters effecting for racemization were identified. (Figure presented.).
Bottari, Giovanni,Afanasenko, Anastasiia,Castillo-Garcia, Antonio A.,Feringa, Ben L.,Barta, Katalin
supporting information
p. 5436 - 5442
(2021/06/17)

Chromium-Catalyzed Production of Diols From Olefins
Processes for converting an olefin reactant into a diol compound are disclosed, and these processes include the steps of contacting the olefin reactant and a supported chromium catalyst comprising chromium in a hexavalent oxidation state to reduce at least a portion of the supported chromium catalyst to form a reduced chromium catalyst, and hydrolyzing the reduced chromium catalyst to form a reaction product comprising the diol compound. While being contacted, the olefin reactant and the supported chromium catalyst can be irradiated with a light beam at a wavelength in the UV-visible spectrum. Optionally, these processes can further comprise a step of calcining at least a portion of the reduced chromium catalyst to regenerate the supported chromium catalyst.
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Paragraph 0111

(2021/03/19)

Preparation of novel biphenyl tetradentate phosphite ligand and application of novel biphenyl tetradentate phosphite ligand in mixed/etherified C4 hydroformylation reaction
The invention discloses a preparation method of a novel biphenyl tetradentate phosphite ligand 2, 2 ', 6, 6'-tetra [(1, 1 'biphenyl-2, 2'-diyl) phosphite]-3, 3 ', 5, 5'- tetra-tert-butyl -1, 1- 'biphenyl and derivatives thereof. The novel biphenyl tetradentate phosphite ligand has a structure as shown in general formula I, wherein a substituent R in the general formula I can be a cyclic phosphinestructure. Meanwhile, the invention discloses an application in a mixed/etherified C4 (butene) hydroformylation reaction system taking a novel biphenyl tetradentate phosphite ligand as a ligand.
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Paragraph 0076-0080

(2020/11/23)

Continuous gas-phase hydroformylation of but-1-ene in a membrane reactor by supported liquid-phase (SLP) catalysis
Process intensification is a cornerstone to achieve a significant reduction in energy consumption and CO2emissions in the chemical industry. In this context, a monolithic membrane reactor combining homogeneous catalytic gas-phase hydroformylation of but-1-ene with in situ product removal is here presented. The homogeneous supported ionic liquid-phase (SILP) catalyst consists of a Rh-biphephos complex dissolved in 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [C2C1Im][NTf2] and immobilized on a mesoporous silicon carbide monolith. The resulting monolith is catalytically active and selective towards linear aldehyde formation, but the accumulation of aldehyde products and high boilers in the ionic liquid leads to slow catalyst deactivation. This accumulation is suppressed when bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate is used as alternative solvent, where only marginal aldehyde accumulation and aldol formation occur. A polydimethylsiloxane (PDMS) membrane coating of the monolith increases the aldehyde-alkene ratio by an enrichment factor of 2.2 in the permeate gas compared to the retentate gas from the reactor simplifying further downstream processing. The monolithic membrane reactor loaded with SILP or SLP catalysts presents a scalable, versatile platform to achieve process intensification for diverse hydroformylation reactions as well as related gas-phase reactions.
Fehrmann, Rasmus,Franke, Robert,Haumann, Marco,Hecht, Corinna,José Garciá-Suárez, Eduardo,Logemann, Morten,Marinkovic, Jakob Maximilian,Riisager, Anders,Sch?rner, Markus,Wessling, Matthias
p. 5691 - 5700
(2020/10/21)

Phosphine ligand, preparation method and application thereof
The invention provides a preparation method of a phosphine ligand and application of the phosphine ligand in catalyzing olefin hydroformylation reaction. A structural formula of the phosphine ligand is shown as the specification, wherein R, R1, R2 and R3 are selected from C1-C40 alkyl, alkenyl, alkynyl, and phenyl, substituted phenyl, naphthyl, anthryl, phenanthryl or other aromatic ring and aromatic heterocyclic substituents with higher carbon number. The preparation method of the phosphine ligand comprises the following step: carrying out one-step reaction on an isochroman salt and trisilylphosphine under the promotion of villiaumite. The phosphine ligand has strong stability and coordination ability, and can be well coordinated with cobalt, rhodium and other metals, the obtained complex can be used for hydroformylation reaction of terminal olefin, internal olefin, trisubstituted olefin and tetrasubstituted olefin, the catalyst dosage is small, the reaction conditions are mild, andthe yield and selectivity of aldehyde products are very high.
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Paragraph 0066-0068

(2020/07/13)

Method for preparing aldehyde through hydroformylation of internal olefin
The invention provides a method for preparing aldehyde through hydroformylation of internal olefin. The preparation method is characterized by comprising the following steps: adding a water-soluble rhodium compound, a water-soluble diphosphine ligand, an additive, deionized water and internal olefin into a reaction kettle equipped with a stirrer and a thermocouple; carrying out replacing 3-5 timesby using synthesis gas formed by mixing hydrogen and carbon monoxide according to a volume ratio of 1: 1; carrying out pressurizing to 1.0-5.0 MPa; conducting a reaction for 2-10 hours at a temperature of 60-120 DEG C; and conducting cooling, taking out a reaction product, and performing separating to obtain the product aldehyde.
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Paragraph 0035-0036

(2020/04/29)

High iso Aldehyde Selectivity in the Hydroformylation of Short-Chain Alkenes
The hydroformylation of propene to give predominantly iso-butanal has been achieved; class-leading selectivity is possible even at higher temperatures that deliver fast conversion. Racemic rhodium complexes of bidentate phospholane phosphites derived from tropos-biphenols and unusual solvent systems are the key to the selectivity observed.
Iu, Leo,Fuentes, José A.,Janka, Mesfin E.,Fontenot, Kevin J.,Clarke, Matthew L.
supporting information
p. 2120 - 2124
(2019/01/25)

Chemoselective Hydrogenation of α,β-Unsaturated Carbonyls Catalyzed by Biomass-Derived Cobalt Nanoparticles in Water
Herein, we report highly chemoselective hydrogenation of α,β-unsaturated carbonyls to saturated carbonyls catalyzed by cobalt nanoparticles supported on the biomass-derived carbon from bamboo shoots with molecular hydrogen in water, which is the first prototype using a heterogeneous non-noble metal catalyst for such organic transformation as far as we know. The optimal cobalt nanocatalyst, CoOx@NC-800, manifested remarkable activity and selectivity for hydrogenation of C=C in α,β-unsaturated carbonyls under mild conditions. A broad set of α,β-aromatic and aliphatic unsaturated carbonyls were selectively reduced to their corresponding saturated carbonyls in up to 99 % yields with good tolerance of various functional groups. Meanwhile, a new straightforward one-pot cascade synthesis of saturated carbonyls was realized with high activity and selectivity via the cross-aldol condensation of ketones with aldehydes followed by selective hydrogenation. More importantly, this one-pot strategy is applicable for the expedient synthesis of Loureirin A, a versatile bioactive and medicinal molecule, from readily available starting materials, further highlighting the practical utility of the catalyst. In addition, the catalyst can be easily separated for successive reuses without significant loss in both activity and selectivity.
Song, Tao,Ma, Zhiming,Yang, Yong
p. 1313 - 1319
(2019/01/25)

Double tooth phosphine ligand and its application in the hydroformylation reaction (by machine translation)
The invention discloses a double-phosphine ligand, its general structure is represented by the formula; in the above formula, Ph is phenyl, a, b, c, d, e, f, g, h are the same or different, selected from H, R, OR, NR2 , NO2 Or cyano, R is alkyl or substituted alkyl. The double-phosphine ligand and the transition metal complex to make the metal - phosphine ligand complex can be used for the hydroformylation reaction catalyst, has high activity and linear selectively, in particular based on selected from transition metal Co, Rh complex; and catalytic reaction the amount of phosphine ligand is greatly reduced. The invention of the double-phosphine ligand easy synthesis, low cost of raw materials. (by machine translation)
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Paragraph 0049-0055

(2018/10/19)

Asymmetric α-Allylation of Aldehydes with Alkynes by Integrating Chiral Hydridopalladium and Enamine Catalysis
A palladium-catalyzed asymmetric α-allylation of aldehydes with alkynes has been established by integrating the catalysis of enamine and chiral hydridopalladium complex that is reversibly formed from the oxidative addition of Pd(0) to chiral phosphoric acid. The ternary catalyst system, consisting of an achiral palladium complex, a primary amine, and a chiral phosphoric acid allows the reaction to tolerate a wide scope of α,α-disubstituted aldehydes and alkynes, affording the corresponding allylation products in high yields and with excellent levels of enantioselectivity.
Su, Yong-Liang,Li, Lu-Lu,Zhou, Xiao-Le,Dai, Zhen-Yao,Wang, Pu-Sheng,Gong, Liu-Zhu
supporting information
p. 2403 - 2406
(2018/04/27)

Oxidative Degradation of l-Isoleucine by Au3+ Complexes in Weakly Acid Medium: A Kinetic and Mechanistic Investigation
Oxidative degradation of l-isoleucine (Ileu) by Au3+ complexes has been studied spectrophotometrically in weakly acid medium (acetic acid–sodium acetate buffer, pH range 3.72–4.80) in the temperature range 288–308 K. The reaction is first order with respect to AuIII but complex order (+ and Cl? ions have been found to show inhibiting effect on the reaction rate. Decreasing solvent polarity exerts an adverse effect on the reaction. Au3+ complexes react with the zwitterion form of isoleucine in a one-step two-electron transfer redox process. The reaction passes through intermediate formation of iminic cation, which hydrolyzes to produce 2-methyl butanal, identified by 1H NMR. The activation parameters ΔH≠ and ΔS≠ related to the rate-limiting step of the reaction are evaluated. The derived rate law is in excellent agreement with the experimental results. The kinetic and activation parameters of this investigation have been compared and analyzed with those of the oxidation of l-leucine by gold(III).
Sen, Pratik K.,Maiti, Krishnendu,Pal, Biswajit
p. 363 - 374
(2017/04/07)

Method for producing aldehydes through olefin hydroformylation reaction
The invention relates to a method for producing aldehydes through an olefin hydroformylation reaction, and mainly solves the problems that in the prior art, olefins or olefins containing side-chain radicals are poor in reactivity, and a catalytic system is not stable under weak acidic conditions. The method for producing the aldehydes through the olefin hydroformylation reaction comprises the step that under the conditions that the temperature is 60-130 DEG C and the reaction pressure is 1.0-6.0 MPa, an aldehyde serves as a solvent, olefin hydroformylation is catalyzed with a rhodium compound, a phosphorus compound containing o-methyl and phenyl groups, a hard base pentavalent phosphorus-containing oxide and a bidentate phosphite ester compound to synthesize the aldehydes; according to the technical scheme, the olefin is at least one of isobutene, cis-2-butene, 2,5-dihydrofuran, 1-butene, propylene and ethylene, the problem is well solved, and the olefin can be used for the process of producing the aldehydes through the olefin hydroformylation reaction.
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Paragraph 0027; 0028; 0029; 0030

(2017/04/03)

Method for synthesis of aldehydes by hydroformylation of alkenes on one same set of production equipment
The invention relates to a method for synthesis of aldehydes by hydroformylation of alkenes on one same set of production equipment, and mainly aims to solve the problem of reaction activity decreasing and catalyst poisoning caused by cross of catalyst ligands in the switching process of different catalysts in the prior art. According to the method, at 60-130 DEG C under the reaction pressure of 1.0-6.0MPa in the switching process of different hydroformylation catalysts, a ruthenium compound is added, so that a rhodium compound, a phosphine compound and a bidentate phosphite composition can catalyze the hydroformylation for synthesis of different aldehydes; the alkenes are at least one of isobutene, cis-2-Butene, trans-2-Butene, 1-Butene, propylene and ethylene, by use of the method, the problem of reaction activity decreasing and catalyst poisoning can be well solved, and the method can be used for synthesis of the aldehydes by hydroformylation of the alkenes on one same set of production equipment.
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Paragraph 0030; 0031; 0032; 0033

(2017/08/26)

Rhodium-Complex-Catalyzed Hydroformylation of Olefins with CO2and Hydrosilane
A rhodium-catalyzed one-pot hydroformylation of olefins with CO2, hydrosilane, and H2has been developed that affords the aldehydes in good chemoselectivities at low catalyst loading. Mechanistic studies indicate that the transformation is likely to proceed through a tandem sequence of poly(methylhydrosiloxane) (PMHS) mediated CO2reduction to CO and a conventional rhodium-catalyzed hydroformylation with CO/H2. The hydrosilylane-mediated reduction of CO2in preference to aldehydes was found to be crucial for the selective formation of aldehydes under the reaction conditions.
Ren, Xinyi,Zheng, Zhiyao,Zhang, Lei,Wang, Zheng,Xia, Chungu,Ding, Kuiling
supporting information
p. 310 - 313
(2016/12/30)

N-Pyrrolylphosphines as ligands for highly regioselective rhodium-catalyzed 1-butene hydroformylation: Effect of water on the reaction selectivity
The hydroformylation of 1-butene catalyzed by Rh(acac)(CO)2 with an excess of N-pyrrolylphosphine ligands, L = P(NC4H4)3, PPh2(NC4H4) or PPh(NC4H4)2, was investigated under constant pressure of synthesis gas (4-10 bar, H2/CO = 1) and 2 bar of 1-butene at temperatures ranging from 50 to 80 °C. N-Pyrrolylphosphine ligands facilitated excellent selectivity towards aldehydes and regioselectivity towards linear aldehydes. The application of a higher temperature, the presence of a small amount of water, and a [L]/[Rh] ratio of ca. 13 resulted in the achievement of the highest n/iso values in a short time. A further increase in selectivity was achieved after the addition of water to the reaction mixture. The catalytic performance of the studied systems showed an increase in selectivity (n/iso) with the increase of the number of pyrrolyl groups in phosphine: (P(NC4H4)3 > PPh(NC4H4)2 > PPh2(NC4H4)) > PPh3.
Alsalahi,Grzybek,Trzeciak
p. 3097 - 3103
(2017/08/14)

METHOD OF PREPARING DIENE
The present invention relates to a producing method of diene and, more specifically, to a producing method of diene, comprising a step of carrying out a dehydration reaction by contacting a catalyst with aldehyde, wherein the catalyst has boron phosphate (BPO_4) which is supported in a phosphate-based carrier. The diene produced by the method according to the present invention has excellent selectivity and yield.COPYRIGHT KIPO 2016
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Paragraph 0055-0063

(2017/01/12)

Visible-Light-Induced Efficient Selective Oxidation of Nonactivated Alcohols over {001}-Faceted TiO2 with Molecular Oxygen
In the presence of molecular oxygen, a {001}-faceted nanocrystalline anatase TiO2 catalyst enabled the selective oxidation of nonactivated aliphatic alcohols to the corresponding aldehydes or ketones under visible light. The reaction shows excellent conversion and selectivity towards the formation of the carbonyl products without over-oxidation to the corresponding carboxylic acids. The exceptional reactivity of the catalyst is possibly due to the absorption of visible light originating from a stronger interaction of alcohol with the {001} facet, which facilitates the modification of the band structure of TiO2, thus facilitating the photogenerated hole transfer and subsequent oxidation processes. The experimental results have also been corroborated by first-principles quantum chemical DFT calculations.
Vadakkekara, Raji,Biswas, Abul Kalam,Sahoo, Tapan,Pal, Provas,Ganguly, Bishwajit,Ghosh, Subhash Chandra,Panda, Asit Baran
supporting information
p. 3084 - 3089
(2016/11/13)

Synthesis and characterization of a magnetically recoverable molybdenum(VI) nanocatalyst for eco-friendly oxidation of alcohols
A catalyst based on immobilization of a molybdenum(VI) Schiff base complex on γ-Fe2O3 magnetic nanoparticles has been synthesized and characterized. This catalyst was employed for the selective oxidation of alcohols to the corresponding carbonyl compounds in EtOH/H2O2. The catalyst can be easily separated from the reaction mixture by decantation using an external magnet and reused efficiently in five subsequent reaction cycles without any significant decrease in activity or selectivity.
Saeednia,Ardakani, M. Hatefi,Parizi, Z. Pakdin,Hafshejani, M. Tavakoli
p. 767 - 774
(2016/09/13)

Highly dispersible and magnetically recyclable poly(1-vinyl imidazole) brush coated magnetic nanoparticles: An effective support for the immobilization of palladium nanoparticles
A heterogeneous recoverable catalyst was prepared via the complexation of palladium onto the surface of magnetic nanoparticles coated by a poly(1-vinyl imidazole) brush. The stable, active and reusable catalyst was proven to be highly active in aerobic oxidation of primary and secondary alcohols with excellent yields. Only 0.1 mol% of the catalyst was used to oxidize 1 mmol of primary and secondary alcohols. The catalyst was readily recovered and reused up to 10 times under the described reaction conditions without significant loss of activity.
Pourjavadi, Ali,Safaie, Niloofar,Hosseini, Seyed Hassan,Bennett, Craig
p. 1729 - 1736
(2016/02/19)

BISPHOSPHITE MIXTURE AND USE THEREOF AS A CATALYST MIXTURE IN HYDROFORMYLATION
The invention relates to a mixture of bisphosphites, to a process for preparation thereof, and to the reaction thereof with metals to give mixtures comprising complexes of the constitutionally isomeric bisphosphites and the metal, and to the use thereof as a catalytically active composition in hydroformylation reactions, and also to the hydroformylation reaction itself.
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Paragraph 0233-0235

(2015/12/20)

Metallopeptoids as efficient biomimetic catalysts
Metallopeptoid catalysts incorporating phenanthroline-copper and TEMPO, and at least one non-catalytic group perform in the oxidation of various benzylic, allylic and aliphatic primary alcohols with a TON of up to 16 times higher than a mixture of the two catalytic groups or the peptoid dimer that is lacking the non-catalytic group.
Prathap, Kaniraj Jeya,Maayan, Galia
supporting information
p. 11096 - 11099
(2015/07/02)

Rapid determination of enantiomeric excess of α-chiral aldehydes using circular dichroism spectroscopy
A method for enantiodiscrimination of α-chiral aldehydes is reported. The method utilizes circular dichroism (CD) spectroscopy and a sensing ensemble composed of 2-(1-methylhydrazinyl) pyridine (1) and Fe(II)(TfO)2. Aldehydes react rapidly with hydrazine (1) to form chiral imines, which form complexes with Fe(II). By monitoring the CD bands above 320 nm, one can determine the enantiomeric excess (ee) values of α-chiral aldehydes with an average absolute error of ±5%. The analysis was fast, and thus can have potential applications in high-throughput screening (HTS) of catalytic asymmetric induction.
Barman, Sanmitra,Anslyn, Eric V.
p. 1357 - 1362
(2014/02/14)

Chiral propargylic cations as intermediates in SN1-type reactions: Substitution pattern, nuclear magnetic resonance studies, and origin of the diastereoselectivity
Nine propargylic acetates, bearing a stereogenic center (-C*HXR 2) adjacent to the electrophilic carbon atom, were prepared and subjected to SN1-type substitution reactions with various silyl nucleophiles employing bismuth trifluoromethanesulfonate [Bi(OTf)3] as the Lewis acid. The diastereoselectivity of the reactions was high when the alkyl group R2 was tertiary (tert-butyl), irrespective of the substituent X. Products were formed consistently with a diastereomeric ratio larger than 95:5 in favor of the anti-diastereoisomer. If the alkyl substitutent R2 was secondary, the diastereoselectivity decreased to 80:20. The reaction was shown to proceed stereoconvergently, and the relative product configuration was elucidated. The reaction outcome is explained by invoking a chiral propargylic cation as an intermediate, which is preferentially attacked by the nucleophile from one of its two diastereotopic faces. Density functional theory (DFT) calculations suggest a preferred conformation in which the group R2 is almost perpendicular to the plane defined by the three substituents at the cationic center, with the nucleophile approaching the electrophilic center opposite to R2. Transition states calculated for the reaction of allyltrimethylsilane with two representative cations support this hypothesis. Tertiary propargylic cations with a stereogenic center (-C* HXR2) in the α position were generated by ionization of the respective alcohol precursors with FSO3H in SO2ClF at -80 C. Nuclear magnetic resonance (NMR) spectra were obtained for five cations, and the chemical shifts could be unambiguously assigned. The preferred conformation of the cations as extracted from nuclear Overhauser experiments is in line with the preferred conformation responsible for the reaction of the secondary propargylic cations.
Nitsch, Dominik,Huber, Stefan M.,Poethig, Alexander,Narayanan, Arjun,Olah, George A.,Prakash, G. K. Surya,Bach, Thorsten
supporting information
p. 2851 - 2857
(2014/03/21)

Identification, characterization, and application of three enoate reductases from Pseudomonas putida in in vitro enzyme cascade reactions
Enoate reductases are versatile enzymes for the enantio- and regioselective addition of hydrogen to double bonds. We identified three EREDs (XenA, XenB, NemA) from Pseudomonas putida ATCC 17453 through a sequence motif search. In addition to cloning, functional expression, and biochemical characterization of these enzymes, the enoate reductases were also applied in enzyme cascade reactions in combination with a Baeyer-Villiger monooxygenase and an alcohol dehydrogenase to produce lactones. Good things come in threes: The identification, cloning, expression, and characterization of three enoate reductases from Pseudomonas putida reveal broad substrate scope and high stereoselectivities. Furthermore, the enoate reductases could be integrated into cascade reactions together with an alcohol dehydrogenase and a Baeyer-Villiger monooxygenase.
Peters, Christin,Koelzsch, Regina,Kadow, Maria,Skalden, Lilly,Rudroff, Florian,Mihovilovic, Marko D.,Bornscheuer, Uwe T.
p. 1021 - 1027
(2014/05/06)

Expanding ester biosynthesis in Escherichia coli
To expand the capabilities of whole-cell biocatalysis, we have engineered Escherichia coli to produce various esters. The alcohol O-acyltransferase (ATF) class of enzyme uses acyl-CoA units for ester formation. The release of free CoA upon esterification with an alcohol provides the free energy to facilitate ester formation. The diversity of CoA molecules found in nature in combination with various alcohol biosynthetic pathways allows for the biosynthesis of a multitude of esters. Small to medium volatile esters have extensive applications in the flavor, fragrance, cosmetic, solvent, paint and coating industries. The present work enables the production of these compounds by designing several ester pathways in E. coli. The engineered pathways generated acetate esters of ethyl, propyl, isobutyl, 2-methyl-1-butyl, 3-methyl-1-butyl and 2-phenylethyl alcohols. In particular, we achieved high-level production of isobutyl acetate from glucose (17.2 g l -1). This strategy was expanded to realize pathways for tetradecyl acetate and several isobutyrate esters.
Rodriguez, Gabriel M,Tashiro, Yohei,Atsumi, Shota
p. 259 - 265
(2014/04/03)

Novel spiroketal-based diphosphite ligands for hydroformylation of terminal and internal olefins
Spiroketal-based diphosphite ligands have been developed for the rhodium-catalyzed hydroformylation reaction. Under the optimized reaction conditions, a turnover number (TON) of up to 2.4 × 104 and a linear to branched ratio (l/b) of up to 93 were obtained in the hydroformylation of terminal olefins. The catalysts were also found to be effective in the isomerization-hydroformylation of some internal olefins.
Jia, Xiaofei,Wang, Zheng,Xia, Chungu,Ding, Kuiling
p. 1901 - 1904
(2013/07/26)

HYDROFORMYLATION PROCESS
A combination of calixarene bisphosphite ligand and an organophosphine ligand. The combination can be employed with a catalytic metal to form a complex catalyst. The catalyst can be employed in a hydroforaiylation process for producing a mixture of aldehydes.
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Paragraph 0051

(2013/08/15)

Stereoselective synthesis and absolute configuration determination of xylariolide A
The asymmetric synthesis of the antibacterial and antitumoral natural compound xylariolide A (1) and five stereoisomers has been achieved. The strategy is based on the one-pot epoxidation/lactonisation or dihydroxylation/lactonisation of the hypothetical biosynthetic intermediate xylarioic A acid (8). The absolute configuration of xylariolide A was thus determined to be 3R,4S,5R,1′R,2′R after the synthesis of 1, two epimers, i.e., 1′-epi-xylariolide A (3) and 2′-epi-xylariolide A (4), and three more diastereoisomers 5-7.
Botubol, Jose Manuel,Macias-Sanchez, Antonio J.,Collado, Isidro G.,Hernandez-Galan, Rosario
p. 2420 - 2427
(2013/05/22)

Ligand-modified rhodium catalysts on porous silica in the continuous gas-phase hydroformylation of short-chain alkenes-catalytic reaction in liquid-supported aldol products
Ligand-modified Rh complexes were physically adsorbed on the surface of porous silica. The resulting materials were subjected to the continuous gas-phase hydroformylation of C2 and C4 alkenes. The ligands used for catalyst modification were bidentate phosphorus ligands known from the literature, namely, sulfoxantphos (1) and a benzopinacol-based bulky diphosphite 2. The tested catalyst materials were active and, in particular, selective as in comparable homogeneous liquid-phase experiments. Long-term stability experiments over 1000h on stream showed minor deactivation. A significant increase in the catalyst mass after the reaction was detected by weighing and thermogravimetric analysis. By using headspace-GC-MS, the mass increase could be attributed to high-boiling compounds, which are formed insitu during the catalytic reaction itself and accumulate inside the pores of the support. Evidence is given that the initially physisorbed catalyst complexes dissolve in the high-boiling aldol side-products, which are suitable solvents for the active catalyst species and provide a liquid-phase environment held by capillary forces on the support. It's all in the pores! Ligand-modified Rh complexes are physically adsorbed onto the surface of porous silica and the resulting solid materials are subjected to continuous gas-phase hydroformylation of C2 and C4 alkenes. The catalyst materials were surprisingly active and, in particular, exhibited similar selectivity to liquid-phase reactions.
Schoenweiz, Andreas,Debuschewitz, Jonas,Walter, Simon,Woelfel, Rene,Hahn, Hanna,Dyballa, Katrin M.,Franke, Robert,Haumann, Marco,Wasserscheid, Peter
p. 2955 - 2963
(2013/10/21)

USE OF OXAZOLINES AS AROMA/FLAVOUR PRECURSORS
The present invention relates to compounds based on an oxazoline moiety which liberate Strecker aldehydes under mild and controllable conditions. In addition the invention relates to food products comprising such compounds, and uses of such compounds.
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(2013/10/21)

From olefins to alcohols: Efficient and regioselective ruthenium-catalyzed domino hydroformylation/reduction sequence
Exploring the alternatives: Ruthenium imidazoyl phosphine complexes catalyze the domino hydroformylation/reduction of alkenes to alcohols in good yields and with good selectivities (see scheme). Linear aliphatic alcohols are synthesized under reaction conditions typically used in industrial hydroformylations. Copyright
Fleischer, Ivana,Dyballa, Katrin Marie,Jennerjahn, Reiko,Jackstell, Ralf,Franke, Robert,Spannenberg, Anke,Beller, Matthias
supporting information
p. 2949 - 2953
(2013/04/10)

Operando infrared spectroscopic and quantum-chemical studies on iridium-catalyzed hydroformylation
Hydroformylation of 1-butene using a triphenylphosphine-modified iridium catalyst was investigated by operando infrared spectroscopy. The spectra were interpreted by comparison with quantumchemically calculated vibrational spectra at the density functional theory level. The processes during activation of the catalyst and hydroformylation were investigated in detail, and the results are discussed. The recently discovered phenomenon of activity enhancement in iridium-catalyzed hydroformylation by a preceding activation step, in which the reaction mixture is treated with synthesis gas containing an excess of carbon monoxide under pressure, could be correlated with the appearance of a complex HIr(PPh3)(CO)3. The similarities and differences between iridium- and rhodium-catalyzed hydroformylation are discussed.
Hess, Dieter,Koenig, Matthias,Reckers, Matthias,Buchholz, Stefan,Franke, Robert,Hannebauer, Bernd
p. 1061 - 1069,9
(2020/09/16)

Production of C5 carboxylic acids in engineered Escherichia coli
Valeric acid and 2-methylbutyric acid serve as chemical intermediates for a variety of applications such as plasticizers, lubricants and pharmaceuticals. The commercial process for their production uses toxic intermediates like synthesis gas and relies on non-renewable petroleum-based feedstock. In this work, synthetic metabolic pathways were constructed in Escherichia coli for the renewable production of these chemicals directly from glucose. The native leucine and isoleucine biosynthetic pathways in E. coli were expanded for the synthesis of valeric acid and 2-methylbutyric acid (2MB) respectively by the introduction of aldehyde dehydrogenases and 2-ketoacid decarboxylases. Various aldehyde dehydrogenases and 2-ketoacid decarboxylases were investigated for their activities in the constructed pathways. Highest titers of 2.59 g/L for 2-mthylbutyric acid and 2.58 g/L for valeric acid were achieved in shake flask experiments through optimal combinations of these enzymes. This work demonstrates the feasibility of renewable production of these high volume aliphatic carboxylic acids.
Dhande, Yogesh K.,Xiong, Mingyong,Zhang, Kechun
p. 1965 - 1971
(2013/02/25)

METHOD FOR SEPERATING 1-BUTENE FROM C4-CONTAINING HYDROCARBON STREAMS BY HYDROFORMYLATION
The invention relates to a method for separating 1-butene from C4-containing hydrocarbon mixtures, comprising isobutene and 1-butene, by hydroformylation, wherein the catalytic system used is made of one of the transition metals of the group 8 to 10, preferably rhodium, and a bisphosphite ligand of the formula (I), where X is a divalent substituted or unsubstituted bisalkylene or bisarylene group having one or more heteroatom(s), Y is a divalent substituted or unsubstituted bisarylene or bisalkylene group having one or more heteroatom(s), Z is oxygen or NR9, and R1, R2, R3, R4 are identical or different, substituted or unsubstituted, linked, unlinked or condensed aryl or heteroaryl groups, and R9 is hydrogen or a substituted or unsubstituted alkyl or aryl group having one or more heteroatom(s), wherein the bisphosphite ligand of the formula (I) is used in an excess of a molar ratio of 100:1 to 1:1 to the transition metal, and that with a 1-butene conversion of more than 95% less than 5% of the present isobutene is reacted method for separating 1-butene from c4-containing hydrocarbon streams by hydroformylation
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(2011/04/18)

HYDROFORMYLATION PROCESS WITH A DOUBLY OPEN-ENDED BISPHOSPHITE LIGAND
A continuous hydroformylation process for producing at least one aldehyde product by utilizing a transition metal and a ligand mixture comprising an organopolyphosphite and an organomonophosphine, with improved stability of the organopolyphosphite ligand. The process involves reacting one or more olefinically-unsaturated compounds with carbon monoxide and hydrogen in the presence of an organopolyphosphite ligand and an organomonophosphine ligand, at least one of such ligands being bonded to a transition metal to form a transition metal-ligand complex hydroformylation catalyst. Surprisingly the addition of the organomonophosphine to a Rh/organopolyphosphite catalyst system did not result in a significant loss of reaction rate.
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Page/Page column 15; 16

(2010/11/03)

Supported ionic liquid phase (SILP) catalyzed hydroformylation of 1-butene in a gradient-free loop reactor
The supported ionic liquid phase (SILP) catalysis technology was applied to gas-phase hydroformylation of 1-butene using sulfoxantphos 1 modified rhodium complexes. Kinetic experiments were performed in a fixed bed reactor and compared to a gradient-free gas-phase loop reactor (Berty type). The influence of substrate concentration, temperature and syngas pressure was determined. Data from fixed bed and Berty reactor were found to be in good agreement with respect to activation energy and reaction order. Ex-situ NMR studies of fresh and used SILP catalysts confirmed that the ligand remained intact after prolonged time on stream.
Haumann, Marco,Jakuttis, Michael,Werner, Sebastian,Wasserscheid, Peter
experimental part
p. 321 - 327
(2009/07/10)

Oxidative decarboxylation and deamination of essential amino acids by N-bromonicotinamide - A kinetic study
The kinetics of oxidation of valine, leucine, isoleucine and phenylalanine by N-Bromonicotinamide (NBN) in acetic acid-water in presence of hydrochloric acid has been studied. The reaction shows inverse order dependence on oxidant and [H+]. Increase in [amino acid] has a slight positive effect on the rate, indicating fractional order dependence. Addition of salts like K 2SO4, Na2SO4, KCl to the reaction medium has no effect on the rate. Increase in temperature increases the rate of the reaction. The activation parameters have been computed. A mechanism consistent with the results has been proposed.
Pushpalatha,Vivekanandan
experimental part
p. 475 - 480
(2010/07/05)

A CALIXARENE BISPHOSPHITE LIGAND FOR USE IN HYDROFORMYLATION PROCESSES
A calixarene bisphosphite composition for use as a ligand in a transition metal-ligand complex catalyst and in a complex catalyst precursor. The ligand is especially useful in catalysts and catalyst precursors for hydroformylation processes wherein a raffinate stream comprising a mixture of alpha, beta, and iso-olefinic isomers is hydroformylated in the presence of carbon monoxide, hydrogen, and the transition metal-ligand complex catalyst to form a mixture of linear and branched aldehyde products. The complex catalyst selectively converts the alpha and beta olefin reactants more rapidly than the iso-olefin reactant resulting in an improved molar ratio of normal (linear) to branched aldehyde products. The unconverted iso-olefinic isomer is thereafter readily separated from the aldehyde product mixture.
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Page/Page column 23-24; sheet 1

(2008/12/04)

Alcohol oxidation in ionic liquid with UHP and recyclable amberlite IR-120 acidic resin: A green approach
Amberlite IR-120 acidic resin, an age old polymer matrix, plays a significant role as catalyst in the oxidation of aromatic alcohols with urea-hydrogen peroxide in ionic liquid at 70°C to disproportionate into phenols and carbonyl compounds in 30-60 min following two pathways. Under similar condition tertiary aromatic alcohol gave exclusively monohydroxyphenol accompanied by acetone. However, aliphatic and alicyclic alcohols yielded carbonyl compounds in moderate to good yields in 1-5 h. Copyright
Bhati, Nishi,Sarma, Kuladip,Goswami, Amrit
p. 496 - 497
(2008/09/21)

Highly stereoselective allylic ethylation with alkoxytitanacyclopropane reagents. Synthesis of (1R/S,7R)-1,7-dimethylnonyl propanoate, the Western corn rootworm sex attractant
Allylic ethylation of 2-((E)-dodec-2-en-4-yloxy)tetrahydro-2H-pyran with ethylmagnesium bromide in the presence of titanium(IV) isopropoxide proceeds via a SN2′ pathway to afford (E)-3-methyltridec-4-ene with excellent syn-diastereoselecivity. This transformation is used as a key step in the synthesis of (1R/S,7R)-1,7-dimethylnonyl propanoate, the Western corn rootworm (Diabrotica virgifera virgifera) sex attractant.
Isakov, Vladimir E.,Kulinkovich, Oleg G.
scheme or table
p. 6959 - 6961
(2009/04/07)

Conversion of oximes to carbonyl compounds by triscetylpyridinium tetrakis(oxodiperoxotungsto) phosphate (PCWP)-mediated oxidation with hydrogen peroxide
Aromatic and aliphatic oximes have been deoximated in chloroform-water to the corresponding aldehydes with dilute hydrogen peroxide and triscetylpyridinium tetrakis (oxodiperoxotungsto) phosphate as catalyst. The presence of dipolarophiles in the reaction mixtures allows a competitive reaction that converts oximes into isoxazole and isoxazoline derivatives via the intermediate formation of nitrile oxide species.
Ballistreri, Francesco P.,Chiacchio, Ugo,Rescifina, Antonio,Tomaselli, Gaetano,Toscano, Rosa M.
p. 1230 - 1237
(2008/12/21)

Determinants of substrate specificity in KdcA, a thiamin diphosphate-dependent decarboxylase
Thiamin diphosphate-dependent decarboxylases catalyze the non-oxidative decarboxylation of 2-keto carboxylic acids. Although they display relatively low sequence similarity, and broadly different range of substrates, these enzymes show a common homotetrameric structure. Here we describe a kinetic characterization of the substrate spectrum of a recently identified member of this class, the branched chain 2-keto acid decarboxylase (KdcA) from Lactococcus lactis. In order to understand the structural basis for KdcA substrate recognition we developed a homology model of its structure. Ser286, Phe381, Val461 and Met358 were identified as residues that appeared to shape the substrate binding pocket. Subsequently, site-directed mutagenesis was carried out on these residues with a view to converting KdcA into a pyruvate decarboxylase. The results show that the mutations all lowered the Km value for pyruvate and both the S286Y and F381W variants also had greatly increased values of kcat with pyruvate as a substrate.
Yep, Alejandra,Kenyon, George L.,McLeish, Michael J.
p. 325 - 336
(2008/02/09)